How should mosaic creators document andamento and opus type for Patreon at the design-decision level?

Andamento documentation for Patreon goes beyond naming the opus type — it explains the design rationale that made that opus choice the correct one for this specific piece. The opus type name (regulatum, vermiculatum, musivum, palladianium) is available in any reference book; the decision why this opus was chosen for this figure against this background is what a patron cannot derive from the finished photograph and cannot find in a tutorial. For opus vermiculatum (a single row of tesserae following the outline of the depicted figure), document the following: the figure's edge complexity (does the subject have simple geometric contours or complex organic edges with fine indentations?), the number of vermiculatum rows used (one row creates a subtle halo; two rows create a more emphatic shadow-line; three or more rows isolate the figure strongly from the background and work best in mosaics where the figure is the sole subject on a flat background), and the tessera size selection for the vermiculatum row (smaller tesserae than the background field allow the row to follow the outline more precisely at concave curves, at the cost of more cutting time). For opus musivum (background lines radiating away from the central figure), document the origin point of the radiation: some creators radiate from the figure's optical center of gravity, others radiate from a point outside the composition to create directional energy, and the difference in visual effect is not derivable from the photograph alone — it requires a process documentation step that shows the radiation-point marked on the substrate before tessera placement. For opus regulatum (a grid of horizontally and vertically aligned tesserae), document why the grid orientation was chosen relative to the composition's primary lines — a regulatum grid aligned with the long axis of a rectangular piece creates different visual tension than a regulatum grid rotated 45 degrees (a rotated regulatum is sometimes called opus palladianium and creates a diamond visual field). Each Patreon post covering a new piece should include a planning photograph or diagram showing the andamento direction marked on the substrate or cartoon before tesserae are placed, and a final photograph from a consistent angle that allows comparison of planned vs realized andamento. The comparison between the cartoon-stage andamento diagram and the finished piece is often the most instructive content a mosaic Patreon post can carry.

How should mosaic creators plan and document tesserae palettes for representational work on Patreon?

Tesserae palette planning for representational work is a two-stage process — value mapping followed by color family assignment — and both stages generate documentation content that patrons cannot reconstruct from the finished mosaic alone. The value mapping stage: convert the reference photograph to greyscale (in any image editor) and identify the value distribution — the darkest zones, the lightest zones, and the mid-tone range. Map each value zone to a tessera value category: dark (value 1–3 on a ten-point scale), mid-dark (4–5), mid-light (6–7), and light (8–10). The value map is the structural skeleton of the composition; color choices within each value zone are secondary and can vary significantly while the composition reads correctly. Document the value map as an annotated greyscale image with the value zone boundaries marked, plus a photograph of the tessera stock sorted by value category (grouping light, mid, and dark tesserae by value, not by color, before any color selection decisions). The color family assignment stage: within each value zone, assign color families from the available tessera stock. For a face in shadow, the value zone is dark (1–3), but the color family within that zone might be warm brown, cool purple-grey, or neutral grey depending on the light source color and the skin tone depicted. Document the color selection decisions by labeling the specific tessera types and color codes used in each value zone, and explain why each color choice serves the design (warm shadows vs cool shadows, the reflected light color in the darkest shadow zones, the color of the lightest highlight tesserae). A common planning tool is the planning grid: overlay a proportional grid on the reference photograph and a corresponding grid on the substrate (typically a 2cm grid for a 30cm × 40cm panel). The grid allows the artist to transfer approximate tessera-size compositional zones from the reference to the substrate systematically, which makes the placement documentation more reproducible. Document the grid overlay photograph (reference image with grid), the substrate photograph showing the grid, and the annotated transfer showing which tessera color family is assigned to which grid cell in each compositional zone. The combination of value map, color assignment documentation, and grid transfer record is a complete palette planning archive that allows patrons to adapt the planning method to their own compositions.

How should mosaic creators document adhesive-to-substrate compatibility at the surface preparation level for Patreon?

Adhesive-to-substrate compatibility documentation goes deeper than the adhesive type alone — the surface preparation for each substrate type is the variable that most affects long-term bond integrity, and it is almost never documented in mosaic tutorials. The substrate preparation steps before adhesive application are the content that makes the difference between a mosaic that delaminations in three years and one that lasts. MDF board: MDF is the most common substrate for portable indoor mosaic panels, but raw MDF has a porous cut edge and an absorbent face that causes PVA to absorb too quickly before adequate bonding occurs. The preparation protocol is to seal all six faces and all edges with diluted PVA (50% PVA, 50% water), apply two coats, allow each coat to dry completely (approximately two hours per coat at room temperature), then lightly sand with 220-grit sandpaper to remove any raised grain. This sealing step reduces PVA absorption during mosaic work so that the adhesive layer maintains its open time and bonds to the tessera back rather than soaking into the substrate. Document the PVA ratio used, the number of coats, drying time between coats, and whether the sanding step was performed. Plywood board: plywood is structurally stronger than MDF for larger panels but has a grain that runs in alternating directions across its plies, making it slightly more flex-resistant than MDF. The preparation protocol is the same PVA seal, plus the additional step of assessing the grain direction of the face veneer and considering how the panel will be mounted — if the panel will hang as a vertical piece, the long grain of the face veneer should run parallel to the long edge to minimize seasonal flex. Note any knots or voids in the face veneer and fill them with wood filler before sealing; knots can bleed resin that prevents adhesive bonding over the knot area. Fiber cement board (HardieBacker or equivalent): fiber cement board is the highest-durability indoor substrate for mosaic because it is dimensionally stable in humidity changes (unlike wood-based boards), does not require sealing before PVA application, and does not flex under normal indoor installation conditions. The preparation protocol is to wipe the face with a damp cloth to remove dust and allow to dry; no sealing is needed and no PVA dilution step is required. Document the specific fiber cement board brand and thickness because not all fiber cement boards have identical porosity and the PVA open time may vary. Terra cotta (bisque-fired) pots and tiles: unglazed bisque terra cotta is a porous ceramic substrate that bonds well to PVA in dry conditions, but the terra cotta must be sealed with a 50% PVA dilution in the same way as MDF before adhesive application to prevent the raw clay from absorbing the PVA adhesive too quickly. Glazed terra cotta or kiln-fired ceramic: the glaze surface is impermeable and may need mechanical roughening (light scoring with a carbide scribing tool across the glaze surface in a crosshatch pattern) before adhesive application, because PVA cannot form a mechanical bond to a smooth glaze surface. Note in the documentation whether the terra cotta pot had a matte bisque surface or a shiny glaze surface, because the surface type drives the preparation decision. Masonry and concrete for thinset: outdoor masonry and concrete substrates for thinset installation should be clean, dry, and free of paint, form-release compound, or surface sealers — all of these prevent the thinset from bonding to the substrate matrix. The preparation protocol is to wire-brush loose material from the surface, vacuum or blow out dust, and test for surface sealers by sprinkling water on the surface (beading water indicates a sealer; water absorption indicates a clean, unsealed surface). If a sealer is present, grinding or muriatic acid washing removes it; document which method was used. For large surfaces with a smoothed or troweled finish, light scarifying (mechanical abrasion to open the surface) improves the thinset bond by creating micro-texture for mechanical interlocking.

How should mosaic creators measure grout joint width and document grout selection decisions for Patreon?

Grout joint width measurement is the technical basis for the sanded vs unsanded selection decision, and documenting the measurement protocol (rather than just reporting the grout type chosen) gives patrons the decision framework to make the same choice in their own work. The measurement method: after all tesserae are placed and the adhesive is fully cured (not just tack-dry — cured, which for mosaic-grade PVA is typically 24–48 hours), measure the grout joint width in at least five representative locations across the mosaic surface using a pair of calipers. Select locations that include the narrowest joints (where two tesserae were placed very close together), the widest joints (where a cut tessera leaves a larger gap), and several representative mid-range joints. Record all five measurements. The threshold: sanded grout is appropriate for joints measuring 3mm or wider at any representative location; unsanded grout is appropriate for joints uniformly narrower than 3mm. If the joint width distribution straddles the threshold (some joints at 2mm, some at 4mm), unsanded grout is the conservative choice because sanded grout pushed into a 2mm joint will have visible sand texture at the surface and may not compact fully into the narrow space. Document the measurement record explicitly: the five joint width readings, the minimum, maximum, and average, and the grout type selected. Grout color selection documentation: the two primary color strategies are recession (choosing a grout color close to the average mid-tone of the tessera palette, so the grout line recedes and the mosaic reads as a unified surface) and definition (choosing a light or dark grout that contrasts with the tessera colors, emphasizing each individual tessera as a distinct element and making the andamento direction more visible). For representational figurative work, grout recession is typical — a neutral grey-beige grout in the value range of the mid-tones prevents the grout from breaking up the figure's form. For abstract geometric work, grout definition is sometimes used deliberately to make the geometric structure more emphatic. Document the color strategy alongside the grout type: which approach was chosen, and whether the grout color is intended to recede or define. The color shift documentation is the most easily skipped step: cement-based grout typically lightens by 20–40% as it dries and cures over 48–72 hours, and the wet grout color (which can look darker and richer) does not match the cured color (which is significantly lighter). Document the wet color immediately after grouting (a photograph is sufficient) and the fully cured color at 72 hours. For creators who select grout by matching a reference swatch in a hardware store under fluorescent light, the wet-vs-cured shift often produces a surprise; documenting the shift in a Patreon post gives patrons a calibration reference for the same grout line in different curing conditions (temperature and humidity both affect the drying speed and the degree of color shift). Epoxy grout documentation: epoxy grout does not have the wet-to-cured color shift that cement grout has (it cures to a consistent color without the drying-induced lightening), but it has a short working time — typically 20–30 minutes at 21°C — and requires a release agent (a thin soapy water solution or a dedicated epoxy grout release product) applied to the tessera surfaces before grouting to prevent cured epoxy from bonding permanently to the tessera faces. Document the release agent used, the working time observed in the studio temperature, and whether any sections had to be regrouted because the epoxy began to set before cleanup was complete.

What is the Apple Tax for mosaic creators on Patreon, and what does the November 1, 2026 change mean in dollar terms?

The Apple Tax is Apple's 30% fee on iOS-billed app subscriptions, applying to all Patreon subscriptions made through the Patreon iOS app starting November 1, 2026 — both new subscriptions and renewals. For mosaic creators, the relevant figure is the iOS rate of the platform mix that drives Patreon referral traffic. YouTube mosaic technique process tutorials and time-lapse assembly videos run 55–70% iOS — mosaic tutorial audiences are similar to other craft channel audiences, with above-average mobile viewing for process content but some desktop viewing for technique study. Instagram mosaic photography (finished pieces, material spreads, before-and-after substrate-to-finished panels): 75–85% iOS, because Instagram's user base is mobile-primary and visually driven craft content performs strongly in discovery. TikTok mosaic creation content (cutting sequences, grouting, reveal videos): 65–75% iOS. At a Patreon monthly revenue of $250/month with 60% iOS: approximately $250 × 0.60 × 0.30 = $45/month ($540/year). At $350/month with 65% iOS (a mixed YouTube-and-Instagram audience): approximately $350 × 0.65 × 0.30 = $68.25/month ($819/year). At $300/month with 75% iOS (Instagram-primary mosaic creator): approximately $300 × 0.75 × 0.30 = $67.50/month ($810/year). The fix: enable Patreon's web-only billing toggle before October 31, 2026, and update Instagram bio, YouTube channel description link, and TikTok bio to use the direct Patreon web URL rather than the Patreon app deep link. Verify with a test subscription from Safari on an iPhone — a subscription completed through Safari is browser-billed and not subject to the Apple Tax. For mosaic creators whose Patreon primary traffic source is YouTube (which has higher desktop rates than Instagram), the effective blended iOS rate is lower than the Instagram-primary figure, but the fix and verification protocol are identical.

Explainers · 2026-06-26 · ~4,400 words

Patreon for mosaic creators: complete 2026 guide — andamento and opus documentation, tesserae palette planning, adhesive-to-substrate compatibility, and the Apple Tax

Mosaic Patreons retain when they deliver the design-decision documentation that a finished photograph structurally cannot carry: the opus type chosen and the specific reason it was chosen for this composition, the value map that drove tessera color selection, the substrate preparation steps that determine whether the bond holds for a decade, and the grout joint measurement that justifies the sanded-vs-unsanded choice. Mosaic audiences are YouTube and Instagram-primary with above-average iOS rates — Apple Tax exposure begins November 1, 2026.

Who mosaic creators are on Patreon

Mosaic practice divides into several areas with distinct Patreon documentation content. Smalti and vitreous glass mosaicists work with traditional glass mosaic materials and document cutting technique, andamento direction, opus choice rationale, and the material selection logic behind tessera color choices. Found-material and ceramic shard artists use broken china, ceramic, and irregular objects and document compositional andamento decisions for non-uniform shapes — the challenge of andamento with irregular material is that the tile outlines themselves create visual direction independent of the intended andamento, and documenting how the creator reconciles the two is high-value content. Pebble mosaic artists work with natural stone in exterior and garden contexts and document material sourcing, pebble size and shape grading, and mortar selection for outdoor environments. Micro-mosaic and millefiori specialists work at the miniature scale with glass cane cross-sections and document the tools and adhesives appropriate for pieces measured in millimeters rather than centimeters. Each type generates Patreon content that patrons cannot derive from the finished piece, because mosaic is a medium where the decisions made before and during assembly are invisible in the completed work.

A two-tier structure suits most mosaic educators: a Process Documentation tier ($12–20/month) delivering each project’s andamento planning diagram, opus type and rationale, cutting technique record, material selection notes, substrate preparation documentation, and grout and adhesive notes; and an Advanced Technique tier ($30–50/month, capped at 8–10 patrons) adding a quarterly project review where the patron submits a photograph of their current work and the creator identifies cutting technique problems, andamento direction issues, adhesive failures, or grout selection errors.

Andamento and opus documentation at the design-decision level

What andamento documentation is not

Naming the opus type is not andamento documentation. Writing “I used opus vermiculatum around the figure” in a Patreon post tells a patron what type was used but not why it was the correct choice for this composition, how many rows were placed around this specific figure, what tessera size was selected for the vermiculatum rows, or how the creator resolved the andamento direction at a concave edge where the vermiculatum row must turn inward without losing its following-the-contour character. The opus type name is a starting point; the design-decision documentation is the Patreon deliverable.

Opus vermiculatum: the figure-outline row

Opus vermiculatum is a single continuous row of tesserae following the outline of a depicted figure or subject, creating a halo of directed placement that separates the figure from the background field. The documentation decisions: number of rows (one row creates a subtle halo that the background opus begins immediately adjacent to; two rows create a more emphatic boundary; three or more rows strongly isolate the figure and are most appropriate when the figure is the sole subject on a flat, single-color background where the multiple rows will not compete visually with background andamento); tessera size relative to the background field (smaller tesserae in the vermiculatum rows allow the row to follow the contour precisely at concave curves — such as the inside of an elbow or the indentation between fingers — where standard-size tesserae would require large, awkward cut angles to follow the line; document the decision to use smaller tesserae in the vermiculatum and the approximate size used); the handling of complex contour points (acute angles in the figure outline require a cut tessera wedge to follow the turn; the cut angle and the waste percentage on difficult contour sections is calibration data for patrons cutting similar figure types).

Document the vermiculatum row with a close-up photograph of the most complex contour section — the area where the row had to follow the tightest curve or the sharpest angle — and an annotated version of that photograph identifying the specific cut technique used at the difficulty point. The annotated close-up is the highest-value content in the vermiculatum documentation because it is exactly the point in the process that a patron cannot slow down or zoom in on in a video.

Opus musivum: radiating background lines

Opus musivum is a background andamento in which tessera lines radiate outward from a central figure in the manner of light rays, creating a visual field that draws the eye toward the figure from the background. The documentation decisions: the radiation origin point (some creators radiate from the figure’s optical center of gravity — the approximate visual center of the depicted subject; others radiate from a point outside the composition to create directional energy toward a corner or edge; the choice of radiation origin determines the visual energy of the entire background and is completely invisible in the finished piece; document it with a diagram showing the substrate with the radiation point marked and the first set of radiation lines drawn before tessera placement); how the radiation lines resolve at the composition edges (as the radiating lines expand outward they become further apart, which creates increasingly large angular gaps between rows; document whether these gaps are filled with additional tessera cuts, whether some radiation lines are “split” into two lines as they expand, or whether the gaps are left as slightly wider grout joints); the opus at the figure perimeter (opus musivum background tesserae meeting a vermiculatum row at the figure edge must transition from radial direction to contour-following direction; document the width of the transition zone and how the directional change is managed — typically one row of cut tesserae set at 45 degrees to bridge the angular difference).

Opus regulatum and opus palladianium

Opus regulatum (uniform horizontal and vertical grid alignment) is the background andamento of classical Roman floor mosaic and produces a static, stable visual field. Opus palladianium (the same grid rotated 45 degrees to produce a diamond orientation) creates a livelier diagonal visual field. The documentation decision: grid orientation relative to the composition (a regulatum grid aligned parallel to the panel edges creates a stable, contained feeling; a palladianium 45-degree rotation creates visual tension and movement; document which was chosen and the reason — “the diagonal rotation counters the strong horizontal line of the horizon in the composition” or “the parallel alignment reinforces the architectural subject”). The decision is not derivable from the finished piece without the creator’s statement because both opus types appear visually similar in photographs at a distance. A close-up diagram of the grid alignment relative to the panel edges provides the reference patrons need to understand the orientation decision.

Tesserae palette planning for representational work

Value mapping: the structural step

The value map is the structural skeleton of a representational mosaic composition. Color choices are secondary to value; a composition that reads correctly in greyscale will read correctly in color. The value mapping process: convert the reference photograph to greyscale (in any image editor: desaturate, or convert to greyscale mode). Identify the five value zones — dark (roughly the darkest 20% of the tonal range), mid-dark (the next 20%), mid-tone (the middle 20%), mid-light (the next 20%), and light (the lightest 20%). Mark each zone on the greyscale photograph with a color overlay in a distinct hue for each zone (zone color is arbitrary; the greyscale value is what matters). Print or display the annotated value map as the planning reference for the tessera palette assignment.

Map each tessera type in the available stock to a value category by laying tiles on a white surface and photographing them, then desaturating the photograph. The value of each tessera type is visible directly in the desaturated tile photograph. Sort the available stock into the five value zones and set aside all tiles that fall outside the needed value range for this composition — if the subject is a high-key (predominantly light) composition, the dark and mid-dark value bins may contain only a few accent tiles. Document the value assignment for each tile type used in the project with the tile code or product name and the value zone it was assigned to. This is reproducibility data: a patron with a different stock who wants to adapt the composition needs to perform the same value assessment for their own tiles to make an equivalent substitution.

Color family assignment within value zones

Within each value zone, color family selection determines the color character of the composition rather than its structural read. For a human face, the mid-dark value zone (4–5 on a ten-point scale) contains the shadow areas of the face. The color family within that value zone can be warm (brown-orange, warm grey), cool (blue-grey, purple-grey), or neutral (grey), and the choice depends on the primary light source color in the reference photograph and the creator’s stylistic intent. Warm light sources (incandescent, sunset) produce warm shadows; cool light sources (overcast daylight, north window) produce cool shadows. Document the light source color in the reference photograph and the shadow color family chosen in response.

Reflected light in the darkest shadow zones is a subtlety that experienced mosaic artists document but beginners consistently miss. In a darkly shadowed area adjacent to a brightly colored surface (a face next to a red cloth, a figure in front of a blue sky), some of the reflected color from the adjacent surface appears in the shadow. Representing this reflected light in tesserae at value zone 1 or 2 (the darkest) with a small number of tiles in the reflected-light color produces realism that patrons notice but cannot identify the source of from the finished piece. Document the reflected light decision: which adjacent surface, what color the reflected light appears, how many tiles in the reflected-light color were placed in the shadow zone, and in which area of the shadow zone they were concentrated (typically at the edge of the shadow closest to the colored surface).

The planning grid

The planning grid is a proportional grid overlaid on both the reference photograph and the substrate that allows systematic transfer of compositional zones. For a 30 × 40 cm panel with a 2 cm grid, the grid produces 300 cells (15 columns × 20 rows). Each cell on the substrate corresponds to the same proportional cell on the reference photograph. For each cell, the creator assigns a primary color family and value zone from the reference. The grid transfer is documented with two photographs: the reference photograph with the grid overlay (printed or drawn in an image editor), and the substrate photograph after grid lines are drawn with a pencil or chalk line, before any tile placement. The annotated substrate photograph after the color-family assignment (each cell labeled with a brief code: W-L for warm-light, C-D for cool-dark, etc.) is the third documentation step and is the reference a patron follows when working on a corresponding piece.

The grid also functions as a placement progress record. Photographing the substrate at the end of each session shows which cells are complete and which remain. For a Patreon audience, this intermediate-progress series documents the sequence in which the artist works — typically figure before background, detailed center before peripheral areas — and the evolution of the color decision as the piece progresses (color family decisions made early in the process sometimes need adjustment once more of the surrounding context is placed, and documenting those adjustments as they occur is more informative than a post-hoc explanation of why the final color worked).

Adhesive-to-substrate compatibility at the surface preparation level

MDF board

MDF (medium-density fiberboard) is the most common indoor mosaic substrate, but raw MDF has a porous, absorbent face and edge that causes mosaic-grade PVA to soak in before the adhesive layer builds to the thickness needed for a strong tessera bond. The preparation protocol: apply two coats of diluted PVA (50% PVA adhesive, 50% water) to all six faces and all edges. Apply the first coat and allow to dry completely — approximately two hours at 20°C in still air, longer in humid or cold conditions. Apply the second coat and dry again. Lightly sand the sealed face with 220-grit sandpaper to remove any raised fiber grain from the sealing step; vacuum the dust, and the board is ready for mosaic-grade PVA adhesive application. Document the PVA brand and dilution ratio (both matter — some mosaic-grade PVA formulations are already modified and do not dilute to the same consistency as standard PVA at 50%), the number of sealing coats, and whether sanding was performed. A board that receives only one sealing coat and no sanding produces a noticeably different adhesive open time than a properly sealed board, and patrons who skip the preparation step can expect shorter open time and a higher rate of tile repositioning failures.

Plywood board

Plywood is structurally stronger than MDF for larger panels (>40 × 40 cm) because it resists flex better under the weight of tessera and grout. The preparation protocol is the same two-coat diluted PVA seal as for MDF, plus two additional considerations. First, inspect the face veneer for knots and voids: knots can bleed resin over time that migrates through the seal and prevents adhesive bonding over the knot area; fill any knots or voids with interior wood filler before sealing, allow the filler to cure fully, and then sand flush before applying the PVA seal coats. Second, consider the grain direction of the face veneer relative to the panel’s orientation in use: for a panel that will hang vertically on a wall, orienting the long grain of the face veneer parallel to the long edge of the panel minimizes seasonal flex from humidity changes. Document the grain direction and the mount orientation in the project notes.

Fiber cement board

Fiber cement board (Hardiebacker, Durock, or equivalent) is the highest-durability indoor substrate for mosaic because it is dimensionally stable across humidity changes, does not require sealing before adhesive application, and maintains its structural integrity over decades without warping or delaminating. Preparation: wipe the face with a damp cloth to remove surface dust, allow to dry, and apply mosaic-grade PVA directly to the clean surface. No diluted seal coat is needed — the cement face is not absorbent in the way that MDF or plywood face veneer is, and the PVA maintains adequate open time without sealing. Document the specific fiber cement board brand, thickness, and whether the smooth or textured face was used for the mosaic (the textured face provides more mechanical bond area for adhesive; the smooth face is sometimes used for finer work where a flat substrate is needed for precision tessera placement). The weight of fiber cement board is significantly greater than MDF or plywood at the same thickness; document the finished piece weight and the hardware used for wall mounting.

Terra cotta

Unglazed bisque-fired terra cotta pots and tiles are porous substrates that bond well to mosaic-grade PVA in dry indoor conditions, but require the same diluted PVA sealing protocol as MDF to prevent rapid adhesive absorption. For outdoor terra cotta pots, PVA-based adhesive is not appropriate; thinset mortar or a flexible adhesive rated for exterior use is required. Document the terra cotta firing type (bisque vs glazed) because the adhesive protocol differs. Glazed ceramic surfaces are impermeable and require mechanical abrasion before adhesive application: use a carbide scribing tool or a coarse diamond-pad grinding disc to score the glaze surface in a crosshatch pattern (score lines approximately 5 mm apart) to create a mechanical bond surface for the adhesive. Document whether the glazed surface was scored and the tool used; an un-scored glaze surface bonded with PVA will typically delaminate over the first one to three years as the adhesive creeps under the glaze at the edge of each tile.

Masonry and concrete for thinset installation

Permanent outdoor mosaic installation on masonry or concrete substrates requires white polymer-modified thinset mortar. The substrate preparation protocol: brush loose material from the surface with a stiff wire brush, vacuum or compressed-air blow the dust, and test for surface sealers by sprinkling water on the surface — beading water indicates a sealer is present; water absorption indicates a clean, bondable surface. If a sealer is present, mechanical grinding or a muriatic acid wash (diluted to approximately 10% concentration, applied and neutralized with baking soda solution) removes it. Document which method was used and why: mechanical grinding is used when the sealer is an epoxy or polyurethane type that acid does not affect; acid washing is appropriate for calcium-based sealers and form-release compounds. For smoothed or power-troweled concrete, scarifying — mechanical abrasion of the surface to create micro-texture — is required before thinset application because thinset does not bond reliably to smooth, densified concrete without a textured surface for mechanical interlocking. Document whether scarifying was performed and the method (angle grinder with scarifying attachment, or shot blasting for larger areas). The thinset mixing documentation covers dry powder weight, water volume, mixing equipment, and the resting time after mixing (the “slake” period of 5–10 minutes before re-stirring allows the polymer in the modified thinset to fully hydrate for optimal bond and workability).

Grout selection at the joint-width measurement level

Measuring grout joint width

The grout joint width measurement is the technical basis for the sanded vs unsanded selection decision. Measure at least five representative locations across the laid mosaic surface with a pair of calipers after the adhesive is fully cured (not just tack-dry; full cure for mosaic-grade PVA is 24–48 hours). Select measurement locations that include the narrowest joints (where two standard-size tesserae were placed very close together), the widest joints (where a cut tessera leaves a larger gap at the substrate), and several mid-range joints in the body of the composition. Record all five measurements, note the minimum and maximum, and use the minimum to drive the sanded vs unsanded decision. If the narrowest joint in the mosaic measures less than 3 mm, unsanded grout is required even if the majority of joints are wider; sanded grout pushed into a 2 mm joint will leave visible sand texture at the joint surface.

Sanded vs unsanded and the 3 mm threshold

Sanded grout contains fine aggregate that prevents shrinkage cracking in joints wider than 3 mm. Unsanded grout shrinks slightly more on curing but does not produce surface texture problems in narrow joints. The practical decision: for vitreous glass mosaic with small tesserae (1–2 cm) and close spacing, most grout joints are narrower than 3 mm and unsanded grout is appropriate. For larger tesserae (ceramic, smalti, pebbles), wider spacing, or intentionally wide grout lines chosen for visual effect, sanded grout is appropriate. Document the caliper measurements, the minimum joint width, and the grout selection with the rationale explicitly stated: “minimum joint width 1.8 mm at five measurement points; selected unsanded grout because the 3 mm sanded threshold was not crossed at any measurement point.”

Grout color documentation: wet, drying, and cured

Cement-based grout typically lightens by 20–40% as it cures over 48–72 hours, and the wet grout color — which can appear darker, richer, and more saturated — does not represent the cured appearance. Document the grout color selection with three photographs: the grout color on the packaging or the chip swatch (the manufacturer’s reference); the wet grout color in the grouted mosaic immediately after application and cleanup (which will be darker and may appear different in hue from the cured result); and the fully cured grout color at 72 hours (the reference for future use of the same grout line). For creators who use grout colors consistently across projects, this three-photograph archive builds a calibration library: a patron who wants to match the creator’s grout color on a reproduction project can compare their wet grout to the creator’s wet-grout photograph, which is more useful than comparing to the cured result (because the patron’s wet grout is what they see while working).

Grout color strategy documentation: recession (a grout color close to the average mid-tone of the tessera palette, so the grout line does not compete with the tessera color) vs definition (a contrasting grout that emphasizes individual tessera boundaries and makes the andamento direction more visible). Document which strategy was used and whether the result matched the intent — if the cured grout color turned out lighter than planned and crossed from recession into partial definition, note this and the adjusted product selection for the next use.

Epoxy grout: working time and release agent

Epoxy grout is the correct choice for permanently wet environments and for installations subject to chemical exposure. Its primary operational challenges are a short working time (typically 20–30 minutes at 21°C, shorter in warmer conditions) and the need for a release agent on the tessera surfaces to prevent the cured epoxy from bonding permanently to the tessera faces during the cleanup step. Apply the release agent (a proprietary epoxy grout release product, or a thin solution of dish soap and water applied and allowed to dry) to the entire mosaic surface before grouting; the dried release coat allows the grout residue to be removed from the tessera faces before the epoxy cures without the aggressive scrubbing that un-released epoxy requires. Document the release agent product, the working time observed in the studio ambient temperature (20°C vs 28°C working times can differ by 8–10 minutes, which significantly affects how large a section can be grouted at one time), the cleanup method, and whether any sections required regrouting.

Tier structure for mosaic creators

Process documentation tier ($12–20/month): each project’s andamento planning diagram and opus rationale, value map with annotated greyscale photograph, color family assignment notes, cutting technique record (material type, tool used, waste percentage), substrate preparation documentation, adhesive type and open time notes, grout joint measurements, grout selection rationale, wet and cured grout photographs, in-progress photographs from substrate through placement through grouting. Advanced consultation tier ($30–50/month, capped 8–10 patrons): same documentation plus a quarterly project review where the patron submits photographs of their current work and the creator identifies andamento errors, adhesive preparation gaps, or grout selection issues with specific corrective instructions.

Apple Tax for mosaic creator audiences

YouTube mosaic technique tutorials and time-lapse assembly videos: 55–70% iOS. Instagram finished mosaic photography and in-progress process shots: 75–85% iOS. TikTok mosaic creation content: 65–75% iOS. Dollar amounts on November 1, 2026: at $250/month with 60% iOS: approximately $45/month ($540/year). At $350/month with 65% iOS: approximately $68.25/month ($819/year). At $300/month with 75% iOS (Instagram-primary): approximately $67.50/month ($810/year).

The fix: enable Patreon’s web-only billing toggle before October 31, 2026 and update all social bio links to the Patreon web URL. Verify with a test subscription from Safari on an iPhone.

KeepTier is a self-hosted membership page for creators who want 100% of their tier revenue and zero Apple Tax. Plans from $9/month.

Patreon for mosaic creators — SEO guide · Patreon for spinning creators · Patreon for crochet creators · Top Patreon alternatives 2026