Category: Technical Knowledge
Published by: MosaicPeel Technical Team
Last Updated: 2026
Reviewed by: MosaicPeel Product Engineering & Quality Control Department
Quick Answer
This glossary defines 60 mosaic tile industry terms in plain English, organized alphabetically from A to V — covering materials science (tesserae, vitrification), performance standards (DCOF, PEI), installation vocabulary (thinset, back-buttering), and trade/sourcing terms (MOQ, FOB). Use it as a quick reference alongside any technical guide on this site, or bookmark it as a standing resource for your team.
Table of Contents
A–C
Andamento — The visual “flow” or rhythm of tesserae placement in a mosaic, particularly in hand-set artistic work; dictates how light reflects and how the eye moves across the surface.
ANSI — American National Standards Institute; the body that codifies major U.S. tile industry standards, including A137.1 (ceramic tile specifications) and A326.3 (DCOF testing).
Back-buttering — Applying a thin additional layer of thinset directly to the back of a tile or mosaic sheet before setting it, used to achieve full bond coverage. See our installation guide for full technique.
Basketweave — A mosaic pattern alternating horizontal and vertical tile pairs to mimic a woven texture.
Caliber — The measured dimensional consistency (size accuracy) of a tile production batch; used alongside shade to assess batch quality.
Chevron — A pattern using pre-angled rectangular tiles that meet in a continuous, seamless V-shape.
Cementitious grout — Portland cement-based grout, either sanded or unsanded; requires periodic sealing in wet or high-traffic areas.
D–G
DCOF (Dynamic Coefficient of Friction) — A measurement of wet slip resistance, tested per ANSI A326.3. See our full DCOF guide.
Deflection (L/360, L/720) — The maximum allowable substrate flex under load, expressed as a fraction of span length; ceramic/porcelain requires L/360, natural stone requires the stricter L/720.
Delamination — Tile or mosaic separating from its adhesive bond, typically caused by insufficient mortar coverage or moisture intrusion behind the tile.
Dot-mounted — A mosaic backing system using small adhesive dots rather than continuous mesh or paper, offering flexibility for curved surfaces. See our backing systems guide.
Efflorescence — A white, chalky mineral deposit that can form on masonry or grout surfaces as water evaporates and leaves salts behind.
Epoxy grout — A two-part resin grout system (ANSI A118.3) offering zero porosity and chemical resistance; requires no sealing. See our epoxy vs cement comparison.
FCL (Full Container Load) — A shipping arrangement where a single buyer’s cargo fills an entire ocean freight container, typically more cost-efficient per unit than LCL.
FOB (Free On Board) — An Incoterm defining that the seller’s responsibility ends once goods are loaded onto the vessel at the origin port; the buyer arranges freight from that point forward.
Frost wedging — The structural damage caused when water trapped inside a porous tile expands roughly 9% upon freezing, cracking the tile or glaze.
Grade (A–D, natural stone) — A commercial quality classification for natural stone mosaic, from Grade A (minimal defects) to Grade D (significant fissures, decorative vertical use only).
H–L
Herringbone — A pattern arranging rectangular tiles in a repeating 90-degree offset zigzag.
Hexagon mosaic — Six-sided tile arranged in a honeycomb grid; popular for its versatility and, in small formats, strong slip resistance due to grout-joint density.
Impervious — The water absorption classification for tile rated ≤0.5%, the standard for pools, outdoor, and constant-wet applications. See our water absorption guide.
Incoterms — Internationally standardized trade terms (FOB, CIF, CPT, etc.) defining exactly where cost, risk, and responsibility transfer between buyer and seller during shipping.
Lead time — The time between order confirmation and cargo-ready date, not including ocean or air transit time.
LCL (Less than Container Load) — A shipping arrangement where cargo shares container space with other shippers’ goods; more accessible for smaller order volumes than FCL.
Lippage — Uneven tile edges at a joint, typically caused by substrate flatness issues or improper leveling during installation.
M–P
Mesh-backed — The most common mosaic backing system, with tesserae pre-glued to a fiberglass mesh sheet on the tile’s back.
MOQ (Minimum Order Quantity) — The smallest volume a manufacturer will produce or ship per order. See our MOQ and shipping guide.
Mosaic effect — The structural phenomenon by which small-format tile’s high grout-joint density mechanically improves slip resistance compared to large-format tile with an identical finish.
Non-vitreous — The water absorption classification for tile rated above 7%; restricted to dry indoor decorative walls.
OEM (Original Equipment Manufacturer) — A manufacturing arrangement where the factory produces tile to the buyer’s specific design, color, or size requirements.
Paper-faced (face-mounted) — A mosaic backing system with tesserae mounted face-down on paper, removed after mortar setting; the industry standard for submerged pool applications.
PEI rating — A 0–5 scale measuring glazed tile’s resistance to surface abrasion from foot traffic. See our PEI rating guide.
Penny round — A small, circular mosaic tile format, often used for retro-style or curved-surface applications.
Private label — A manufacturing arrangement where an existing or lightly customized product is packaged and branded under the buyer’s own company name.
R–V
Re-tempering — Adding water to thinset or grout that has already begun to stiffen, which weakens the material’s final bond strength; a technique to avoid, not a corrective fix.
Sanded grout — Grout containing sand aggregate, recommended for joints 1/8 inch or wider to add structural strength and reduce shrinkage cracking.
Shade variation — Color inconsistency between tiles, either within a batch or between different production runs; managed through dye-lot tracking and mixing tiles from multiple boxes during installation.
Slaking — A 5–10 minute rest period after initially mixing cementitious grout or mortar, followed by remixing, to improve chemical hydration and final bond strength.
Tesserae — The individual small pieces (glass, ceramic, stone, or other material) that make up a mosaic; the Latin-derived term for the building blocks of mosaic art and tile.
Thinset (thin-set mortar) — Cement-based adhesive mortar used to bond tile to a substrate; available in unmodified and polymer-modified formulations for different applications.
Unsanded grout — Grout without sand aggregate, used for joints under 1/8 inch to avoid scratching delicate glass or polished stone surfaces.
Vitreous — The water absorption classification for tile rated 0.5%–3%; suitable for most indoor use but marginal for constant submersion.
Vitrification — The high-temperature firing process that fuses clay minerals into a dense, glass-like, low-porosity structure — the defining manufacturing step that distinguishes porcelain from standard ceramic.
Waterjet cutting — A precision cutting method using a high-pressure water stream (often mixed with abrasives) to cut complex curved or interlocking custom mosaic shapes without the micro-fractures traditional saw-cutting can cause.
FAQ
What does DCOF mean in tile?
DCOF stands for Dynamic Coefficient of Friction — a standardized laboratory measurement of how slip-resistant a tile surface is under wet, dynamic (walking) conditions, tested per ANSI A326.3.
What is the difference between thinset and mastic?
Thinset is a cement-based mortar that cures through hydration and is suitable for wet and submerged applications when properly formulated. Mastic is a pre-mixed organic adhesive that is water-soluble and will re-emulsify (soften) under constant moisture — making it appropriate only for dry interior applications, never showers or pools.
What are tesserae?
Tesserae is the technical term for the individual small pieces — glass, ceramic, stone, or other material — that make up a mosaic tile. The word derives from the Latin term for “cube” or “dice,” referencing the ancient Roman origins of mosaic tile art.
This glossary is maintained and updated by the MosaicPeel Technical Team as industry terminology evolves. Suggest a term we should add by contacting our technical support team.
Related reading from MosaicPeel:
– How to Install Mosaic Tile: A Professional Guide
– Mosaic Tile Water Absorption Ratings Explained
– DCOF and Slip Resistance: What Importers Need to Know
– Complete Guide to Mosaic Tile MOQ and Shipping
– Mesh-Backed vs Paper-Faced vs Dot-Mounted Mosaic: Backing Systems Explained