Chapter 1 – Stress maps – Sarah Clarity Studios

Chapter 1: Stress Maps

Created by Sarah Choi (prompt writer using ChatGPT)

Stress Maps (Cuffs, Knees, Elbows)

Wear, Weathering & Damage for Costume Concept Artists (Scuffs, Stains, Tears, Repairs)

Equally useful for concept-side ideation and production-side handoff. Written in plain, visual language for concept artists.

1) Why stress maps matter

Stress maps are the “traffic heatmaps” of garments: they predict where friction, flex, impact and contamination concentrate. If you deliberately place scuffs, stains, tears and repairs at these high‑probability zones, your costumes read as lived‑in, story‑true, and production‑feasible. Stress mapping also prevents random-noise weathering that confuses silhouettes.

Primary high‑stress sites on apparel:

Cuffs (sleeve & hem): abrasion, edge fray, grime bands, delamination of coatings, sweat/soot accumulation.
Knees: kneeling scuffs, stretch whitening, thread popping at seam apex, ground‑transfer stains (earth, oil, rust).
Elbows: crease polish, fabric glazing, spider‑micro‑cracks in coatings, patch jobs on points.

Secondary sites (contextual): collar stand, pocket mouths, fly/closure edges, belt loops, inner thighs, seat, shoulder tips (packs/straps), heel counters and toe rands on boots.

2) The readable logic of wear (story > noise)

Think of wear as three interacting layers:

Material physics: fiber type, weave/knit, finish, coating, lining. (What can fail?)
Use patterns: job, habit, posture, environment, carry load, locomotion. (What does stress it?)
Time & care: age, laundering method, repairs, upgrades. (Why hasn’t it failed—or how was it saved?)

Design rule: picking 2–3 specific causes renders clearer than sprinkling small noise everywhere. Eg. “Sand + crawling + oiling tools” > generic brown grunge.

3) Stress atlas by zone (quick reference)

3.1 Sleeve cuffs

Mechanics: contact with surfaces, frequent handwashing line, sweat/salt, UV on edges.
Common reads: edge fuzz, thread whiskers, darker dirt band at fold, polish on hardwear (snaps, rivets), paint flecks.
Failure → repair: sleeve seam unpicking; bias tape added; leather binding; makeshift twine wrap.
Concept cues: focus 3–10 mm from edge for most fabrics; accentuate contrast at fasteners; asymmetry if dominant hand.

3.2 Hem cuffs (pants/skirts/coats)

Mechanics: heel/ground strike, capillary wick of mud, snow salt lines, bike‑chain oil.
Common reads: upward tide line of stain; chewed back‑edge; quilting thread peeks; reflective tape scuff.
Failure → repair: hem re‑turned shorter; iron‑on hem tape show‑through; patch wedge over kick slit.

3.3 Knees

Mechanics: kneeling compression, crawling shear, fabric stretch over patella.
Common reads: whisker‑stars radiating micro‑creases; color lift (denim white‑out); abrasion oval; dust embed.
Failure → repair: darted knee patches, foam insert prints, external caps; sashiko grid, bar‑tack ladders.

3.4 Elbows

Mechanics: hinge creasing, desk/table rub, pack‑strap swing.
Common reads: crease gloss on leather; crackle on coated canvas; thinned nap on wool; polish stripe.
Failure → repair: classic elbow patches (leather, suede), zig‑zag darns, contrast knee‑pad repurposed to elbow.

4) Material‑specific wear grammar

4.1 Denim & cotton twill

Scuffs: high‑frequency micro‑abrasion → lighter blue/white on ridges; darker in valleys.
Stains: oil/grease halos, earth chroma, rust nodes at rivets.
Tears: along weft; fray with white warp whiskers.
Repairs: contrast indigo patches, visible golden topstitch; boro layering.

4.2 Wool (suiting, melton)

Scuffs: nap flattening → sheen bands at elbows; pills at side seams.
Stains: water rings; drink drips (tan/brown); salt tide in winter.
Tears: along bias at stress points; moth bites as pinpoint clusters.
Repairs: darned weave mimic, invisible mending; suede elbow patches.

4.3 Leather & coated textiles

Scuffs: pigment removal on peaks; pull‑up lightening on bends; edge burnish at cuffs.
Stains: oils darken permanently; salt bloom (white bloom) in creases.
Tears: usually at stitch holes; delam in coatings → alligatored cracks.
Repairs: edge paint touch‑ups, hand‑stitched saddlery patches, riveted plates.

4.4 Knits & jerseys

Scuffs: fuzzing, pilling at elbow/knee; cuff stretch splay.
Stains: sweat bloom at cuffs/collar; ink/marker feathering.
Tears: laddering runs; hole expansion with deformation.
Repairs: knit‑in darns, woven patch behind, cover‑stitch rings.

4.5 Synthetics (nylon, poly, softshell)

Scuffs: shiny glaze; feathered micro‑snags; whitening at fold lines.
Stains: dye‑resistant but shows contrast dirt bands; salt rims.
Tears: sharp, clean slits; seam tape peel.
Repairs: seam‑grip glues, heat‑patch films, taped appliqués.

5) Environment → wear matrix (quick pick)

Environment	Scuffs	Stains	Tears	Typical Repairs
Desert	wind‑sand matte, glassed edges	dust tan bands	dry crack in coatings	wrapped scarves at cuffs, leather bindings
Wetlands	soft abrasion, mud smoothing	swamp greens, tide lines	seam rot, thread pop	tar patches, waxed canvas overlays
Urban/Industrial	concrete rub, metal scrape	oil, soot, paint	clean slashes	duct‑tape temp, riveted plates
Snow/Cold	ice polish, salt crystal grind	salt bloom rings	stiffness cracks	fur/knit cuffs, extra seam taping
Ship/Coast	rope burnish, tar	brine, rust	fray at hems	sailcloth patches, palm‑stitched seams

Use 2–3 cells to build a clear wear story.

6) Placement heuristics (fast, believable)

Cuffs: draw a 360° band at edge; break into traffic zones = palm side darker; outer wrist slightly brighter (exposed). Add 2–3 nicks aligned with hand‑to‑surface habits.
Knees: center an oval over patella; add 5–7 radiating crease rays; lighten peaks, dirty valleys. Offset slightly toward dominant kneel pattern (left/right, based on character).
Elbows: establish a hinge line; put a polished groove right on the bend apex; micro‑crazing perpendicular to the groove for coated/leather.
Asymmetry signal: 60/40 split—dominant side shows 1.4× wear intensity.
Gravity logic: stains wick upward (capillary) a short distance; drips travel down with slightly wider base.
Edge logic: damage concentrates at edge + apex of folds; interior planes stay subtler.

7) Values, hue & roughness: selling the read in seconds

Value: scuffs usually lift value (lighter) on raised yarns; stains lower value (darker) and reduce local contrast.
Hue: oils push warmer; rust toward orange‑brown; algae/verdigris toward green; salt rings are desaturated light.
Roughness: polished = lower roughness (shinier); fuzz/fray = higher roughness (matte). Stack both within one zone for rich reads.
Spec edges: at elbows/leather, add a tight specular highlight band only at the sharpest bend—avoid coating the whole elbow.

8) Scuffs, stains, tears, repairs — micro‑libraries

Create 1–2 stamp sheets per category for speed.

Scuffs (micro to macro)

Micro: hairline tick marks aligned to motion; chalky lift on denim ridges.
Macro: broad palm‑sized dull zones on elbows/knees; heel‑chew on hems.

Stains

Rings: liquid tide lines at cuffs, hem.
Halos: oil with soft falloff; layer three values for depth.
Particulate: speckle cluster near source (mud kicked from rear heel).

Tears

Nicks: 2–5 mm cuts at edges; perpendicular to stress direction.
Slashes: 20–50 mm, clean in synthetics, ragged in natural fibers.
Blowouts: knee holes with yarn bridges; underlay visible.

Repairs

Functional: bar tacks, zig‑zag patches, riveted leather tabs.
Decorative‑functional: sashiko grids, boro layers, contrast topstitching.
Field fixes: safety pins, duct tape ghosts, shoe‑goo smears.

Tip: A single repair often clarifies the whole wear narrative better than extra grime.

9) Concept‑side workflow (A/B/C passes)

A‑pass (silhouette & read):

Place 3–5 high‑signal wear clusters only (e.g., left knee, both cuffs, right elbow).
Balance with clean areas so the garment still reads shape & material.

B‑pass (material truth):

Apply the correct micro: denim whiskers vs leather glaze vs knit pilling.
Adjust roughness and edge contrast per material.

C‑pass (story & specificity):

Add 1–2 stains tied to prop/role (ink for scribes; resin for bowyers).
Insert a repair motif consistent with culture/tech (hand‑darn vs heat‑patch).

LOD planning:

Gameplay distance: keep broad bands and 1–2 high‑contrast repairs.
Close‑up: reveal micro‑fibers, stitch types, and layered stains.

10) Production‑side notes (texture/shader callouts)

Mask packs:
- R = scuff intensity; G = stain mask; B = tear/edge fray; A = polish/spec boost.
Channel‑packed AO: bake wrinkle AO around elbows/knees for dirt catchers.
Tiling vs unique: put micro‑noise in tilers; paint macro bands in unique masks.
Edge wear generator: drive with curvature + custom vertex colors painted at cuffs/knees/elbows.
Decals: reserve for event‑specific stains/repairs (fresh blood, wet paint, new patch).
Cloth sims: pin higher friction at cuffs/hems; increase bend stiffness at repaired patches (slightly fewer wrinkles).

11) Role thumbnails (stress signatures)

Miner / salvager: knee blowouts, tar hems, leather cuff wraps, metal dust on elbows.
Courier / rider: asymmetric knee polish (mount side), wind‑burnt cuffs, bug strikes on elbows.
Noble fallen on hard times: immaculate silhouette; one meticulous darn at elbow; faint hem salt lines.
Arctic scout: bright salt blooms at cuffs, ice‑polish on elbows, seam‑tape lifts, knit cuff frost.
Shipwright: rope‑burn cuffs, tar smears, rust freckles at rivets, sailcloth elbow patches.

12) Visual shorthand library (scribble‑ready)

Cuff dirt band: thin, uneven ring + 2–3 vertical drip interrupts.
Knee star: oval plate + 6–8 whisker rays; lighten peaks; speckle valley.
Elbow polish: narrow curved highlight band + perpendicular micro‑cracks.
Repair badge: rectangle patch + offset stitch line + 2 stray thread tails.

13) Color chips (quick picks)

Salt/alkali ring: H 20–40°, S 5–10%, V 85–92%
Oil halo (light fabric): H 30–45°, S 40–55%, V 45–55%
Old rust: H 20–25°, S 65–80%, V 25–40%
Fresh earth (wet): H 15–25°, S 55–70%, V 20–35%
Denim whisker lift: towards V +15–25, S −10–15 (local)

14) Reference prompts (build your board)

“Workwear elbows gloss vs cuff fray macro.”
“Kneeling floor installers—knee pad imprint patterns.”
“Sailcloth repairs—zig‑zag patches, palm stitches.”
“Vintage denim knee blowouts stages 1–5.”
“Salt tide lines on hems in winter cities.”

15) Common mistakes & how to avoid them

Even wash everywhere: breaks material read. → Concentrate wear at edges/apexes.
Mud with no gravity: add drips, splatter direction, and wick lines.
Symmetry: always bias toward dominant side or habitual motion.
Over‑noising leather: reserve crackle for bend apex; keep planes smoother.
Repairs with no cause: place repair over prior stress focus; show stitch tension.

16) Mini case studies (concept → production)

Courier’s trousers (urban)

Concept: right‑side mount → extra wear on right knee & inner calf; oily chain splatter at right hem.
Production: unique mask for right leg knee whiskers; decal cluster for chain oil; vertex‑paint polish on inner calf.

Arctic coat (synthetic shell)

Concept: salt bloom rings at cuffs + tape peel at elbow seam + frost matte.
Production: roughness map with low‑R islands at polish; alpha decals for tape lift; normal map micro‑crackle on elbow.

Scholar’s jacket (wool)

Concept: elbow sheen + ink stains on right cuff + careful darn.
Production: AO dirt catch at cuff seam; spec mask stripe at elbow; micro‑fiber normal for pills.

17) Cross‑cultural repair motifs (use respectfully)

Sashiko (Japan): grid or running‑stitch reinforcement; communicates care, thrift, pride.
Boro (Japan): layered indigos; history visible in patches.
Kintsugi‑adjacent cloth logic: contrast “golden” thread darning to honor damage.
Sailmaker’s palm stitch (nautical): bold zig‑zag; functional & graphic.

Use to tell values (resource‑scarce, ritual care, guild pride). Avoid tokenism: keep motif consistent across the wardrobe set.

19) Variant matrix template (duplicate per character)

Variant	Cuffs	Knees	Elbows	Extra
Clean	crisp edge, no band	faint crease only	no polish	n/a
Worn	narrow dirt ring + 2 nicks	whisker‑star lightening	thin polish stripe	faint hem tide line
Damaged	fray tufts, small tear	hole w/ yarn bridges	crackled coating	one stain ring
Patched	leather binding	sashiko patch	suede elbow pad	label notes + date

20) Quick exercises (skill‑builder)

90‑second maps: draw only the wear zones on five silhouettes; no texture. Repeat for different roles.
Single‑cause pass: pick one cause (salt, oil, sand). Paint it convincingly on cuffs/knees/elbows.
Repair first: design the repair as the hero; then work backward to the damage that required it.
Asymmetry audit: flip all wear layers horizontally—re‑asymmetrize consciously.

21) One‑pager callout template (copy/paste)

Garment: _________ Role: _________ Env: _________

Primary zones: Cuffs □ Knees □ Elbows □ (Other: ____)

Scuffs: where + why → _________

Stains: substance + directionality → _________

Tears: cut/abrade + seam relation → _________

Repairs: technique + material → _________

Material notes: _________

Mask/shader plan: _________

Asymmetry: dominant side & ratio → _________

LOD: gameplay vs close‑up → _________

Final reminder

Lead with cause and material; place wear at edges and hinge‑apexes; keep asymmetry intentional; make one repair sing. If a stranger can guess the character’s job from the cuffs, knees, and elbows, your stress map is doing its job.