Sarah Clarity Studios

Chapter 2: Wear Patterns (Edges, Oils, Stains, Chips, Scorch, Dust)

Created by Sarah Choi (prompt writer using ChatGPT)

Wear Patterns — Edges, Oils, Stains, Chips, Scorch, Dust (Materials & Surface Language)

Purpose and Scope

Wear is the handwriting of use. It reveals how a prop is handled, where it lives, who owns it, and what it has survived. This article gives prop concept artists—both on the concepting side and the production side—a rigorous, material‑aware framework for designing believable wear across wood, metal, plastic, glass, ceramic, fabric, and rubber. It focuses on six core categories—edges, oils, stains, chips, scorch, and dust—and shows how to stage them for camera/game readability while preserving plausible cause‑and‑effect.

Principles of Believable Wear

Believable wear follows contact, motion, and environment. It clusters at grip zones, edges, interfaces, and flow paths; it respects gravity and orientation; and it layers over time. Start with a “use map”: draw three lines—the hand path, the motion path, and the environment path. Hand path covers grips, latches, and maintenance access. Motion path follows sliding, rotating, and vibrating parts. Environment path encodes rain, sun, heat, dust, salt, and chemicals. Place wear only where at least one path overlaps. Then iterate: fresh wear rides above old wear (glossy polishes atop matte chalking; new stains over faded ones), and protected zones retain original finish.

Distance Reads: Long, Mid, Close

At long distance, wear should clarify silhouette and material separation: brightened edges, darkened creases, and high‑contrast grip halos. At mid distance, anchor one or two narrative events (a scorch bloom near a vent, a chipped corner at a drop zone). At close distance, showcase micro‑evidence: fingernail scratches at a latch, oily thumb arcs, speckled rust at fastener heads, dust trapped in stitch valleys. Resist even distribution; stage wear like lighting.

Edges: Where Finish Fails First

Edges collect two opposing effects: abrasion that burnishes gloss on hard materials, and erosion that rounds and lightens on soft ones. On metals and dense woods, high spots polish to a brighter, tighter highlight, revealing base metal or deeper grain. On paints and plastics, edges chip or thin, showing substrate or a lighter chalk. On fabrics and rubbers, edges fuzz, pill, or micro‑crack. Use edge wear to articulate form: selectively pop silhouette turns, but leave shadowed, unreachable edges intact to preserve contrast for hero reads.

Oils: Human Contact, Lubricants, and Sweat

Oils unify mixed materials and point to interaction. Skin oils darken porous surfaces (unfinished wood, fabric), lower roughness on paints and plastics, and create fingerprintable smudges on glass and gloss. Mechanical oils wick along seams, collect in AO, and draw dust that flips gloss back to matte. Salt from sweat whitens leather and rubber at creases. Place oil cues exactly where hands go—the forward third of grips, around buttons and dials, under carry handles—and along service seams where techs would wipe.

Stains: Water, Minerals, Chemicals, and Life

Stains mark fluids and residues. Water leaves vertical tide marks with a darkened wet edge that dries to pale mineral rings (calcium, lime). Coolant crystallizes blue/green; fuel leaves brown, translucent smears with rainbow sheen; battery acid etches paint into chalky streaks; plant saps amber and becomes tacky dust magnets. Food oils yellow paper and wood; mud deposits dry into flake‑off crusts. Stage stain stories by source, path, and age: a concentrated origin point, a directional run, and a terminal fan or drip pattern that aligns with gravity and geometry.

Chips: Impact and Delamination

Chips are discrete impact events. They appear at corners, protrusions, and zones that contact other objects. Paint chips to substrate with feathered edges and small radial cracks; powder coat dents with fewer, softer chips; anodize doesn’t chip—its color thins and scuffs; ceramics chip sharply with bright, vitreous edges; plastics gouge rather than chip, leaving smeared, lighter material. Cluster chips near loading points and simulate “ghost chips” where follow‑on overpaint partially fills older losses, leaving soft rim echoes.

Scorch: Heat, Arcing, and Soot

Heat paints materials with physics. Metals show straw→brown→purple→blue heat tints in stainless, dark oxide blooms on carbon steel, and anodize discoloration near welds. Paint browns, gloss drops, and bubbles; plastics gloss, sag, and soot; wood chars to alligator skin; fabric singes, curling fibers and leaving crisp edges. Soot moves with airflow, caking upstream of leaks and tracing vents as crescent halos. Electrical arcing spawns star‑burst pits and metallic “ghosting.” Keep scorch gradients directional and tie them to heat sources or exhaust paths to avoid random “FX stickers.”

Dust: Deposition, Entrapment, and Wipe Logic

Dust is the great equalizer. It settles on upward‑facing surfaces, lodges in horizontal grooves, and fails to stick where vibration or handling occurs. Thickness varies with shelter and climate; color varies with locale (red ochres, gray concrete, yellow pollen). Dust highlights human cleaning: finger swipes, rag arcs, and clean halos around labels and inspection windows. A convincing dust pass alternates matte accumulation in dead zones with polished tracks in hand paths—this contrast sells life and motion.

Material‑Specific Wear Language

Wood

Unfinished or oiled woods darken at grips from oils and lighten where abrasion cuts through oxidized surface layers. Edges round and show lighter fresh fibers at first, then darken with grime. Varnished or lacquered woods chip and craze at corners; gloss concentrates along long grain where sanding was finer. Water rings appear around standing moisture; iron fasteners stain wood black where wet. Burnishing from straps or rope leaves smooth, darker grooves. Place micro‑dents around fasteners, and let seasonal movement open hairline cracks across boards.

Metal

Steel: edge polishes to bright metallic; rust begins at breaks in coating and around fasteners, bleeding downward in narrow fingers; repeated rubs flatten mill scale into satin. Aluminum: oxide is white/gray; abrasion smears and brightens; pitting occurs in salt. Stainless: heat tints, tea‑stain rust in chloride environments, and polished tracks at hand paths. Painted metals chip to primer, then to metal; exposed metal rusts, then stains adjacent paint. Use weld toes as grime traps and show directional sanding marks near repairs.

Plastic

Color‑through plastics lighten with scuffs and show raised burrs at gouges. UV chalking whitens top faces; edges get glossy where hands polish. Soft‑touch coatings turn patchy glossy, then peel. Mold parting lines catch dirt; screw bosses telegraph as circular stain halos. Adhesive label ghosts remain as clean rectangles. For brittle plastics, show corner cracks radiating from fastener holes; for ductile ones, show cold‑flow creep around constant loads (sagging handles).

Glass

Fingerprints, breath fog, and wiper arcs dominate. Micro‑scratches create fine “star” scintillation in highlights and a fogged look at grazing angles. AR‑coated glass shows faint blue/purple hue shifts; worn AR reveals brighter patches in the swipe center. Hard water leaves ringlets and drip fans; silicone smear halos appear around sealed edges. For cracked glass, show streaked dirt trapped in crack lines and a clean spot where tape recently covered a break.

Ceramic

Glossy glaze chips reveal sharp, light cores; crazing collects dark grime; matte glazes polish along contact zones into satin islands. Unglazed clay drinks oils and water, creating dark tide lines; lime deposits crust where water boils or evaporates. Kiln‑glaze pooling leaves thicker, glossier concave corners—these chip differently than thin edge glaze.

Fabric

Weave and fiber drive wear. High‑friction zones grow glossy from fiber alignment; edges fuzz and pill; color shifts where sun fades exposed panels. DWR beading dies at creases, leaving wet‑out patches. Stitch valleys capture dust; bar tacks fray. Grease and sweat halo around pockets and straps. Knees and elbows lighten; knees also pick up ground‑tone stains specific to locale. Repair patches show contrast in weave direction and dye lot.

Rubber

New rubber presents a smooth satin. With time, bloom whitens surfaces; dust embeds stubbornly; crease lines gray and micro‑crack from ozone. Edges abrade into rounded, lighter lips; molded lettering retains contrast as surrounding surfaces polish. Heat near exhaust browns natural rubber; oils swell some elastomers, creating sticky gloss. Paint marks smear quickly; engravings persist.

Environment Dialects: Desert, Coastal, Industrial, Cold

Desert: UV chalking, wind‑scoured satin, phasey dust with directional streaks, parched leather, brittle plastics. Coastal: salt bloom, galvanic rash at mixed metals, tea‑stain on stainless, damp fabric darkening, verdigris near copper and brass. Industrial: soot veils, oily grime in AO, abrasive grit that cuts glossy edges to matte; enamel signage ghosts. Cold: condensation halos, lacquer checking, rubber hardening with white crease lines, rust slowed but salt aggressive on roads.

Workflow: From Concept Intent to Production Fidelity

Concept side: produce a “wear map” layered over the prop—edges, oils, stains, chips, scorch, dust—each with a one‑sentence cause. Provide a value‑only wear preview to ensure read without hue. Include micro‑vignettes (3–4 tiles) that demonstrate the material‑specific language for your prop. Production side: build wear in causality order—substrate → finish → mechanical damage → fluids → dust. Use AO and curvature as helpers, then hand‑paint path‑of‑use. Vary roughness more than color for subtlety; reserve color pops for stains and heat tints. In physical builds, pre‑stage hand paths and scuff with actual use: carry, set down, holster—then lock with clear.

Narratives in Time: Fresh, Settled, Ancient

Fresh wear: bright, crisp, high contrast—wet oils, sharp chips, soot not yet blended. Settled wear: softened edges, dust infill, slight corrosion growth, dried stain rims. Ancient wear: rounded forms, homogenous matte, deep staining in pores, layered repair over ghosts of older states. Choose one era as dominant and season with the others to avoid muddiness.

Red Flags and Corrections

Avoid uniform “edge wear outlines,” omnipresent scratches, or dust on vertical faces without cause. Don’t duplicate decals of grime; repeat with intent. Ensure wear does not compromise function unless story demands it—if it does, add a compensating fix nearby. Align drip paths with gravity; align polishing with hand reach; stop wear under gaskets and overlaps. When in doubt, remove 30% of your grunge and concentrate the remainder.

Deliverables and Callout Language

Ship: (1) a hero render, (2) a grayscale wear map, (3) material close‑ups per category, (4) a short “wear logic” memo listing causes by zone (“Grip: skin oils + micro‑scratches; Vent: soot halo, vertical streaks; Base: desert dust plateaus, wipe arcs around labels”). Include notes for shader controls (roughness boosts, clearcoat thinning, anisotropy direction) so the finish reads under changing lighting.

Final Thoughts

Wear is not decoration—it is biography. When edges, oils, stains, chips, scorch, and dust answer to how a prop is used and where it lives, surfaces become truthful. Lead with paths of use, respect material physics, and layer time thoughtfully. Your props will feel handled, necessary, and alive.