To grade moth damage on a used cashmere sweater, hold the knit up to a bright light, then stretch the suspect area gently. Open holes with cut or missing yarn are moth damage and usually cap the sweater at Fair or lower; translucent patches that spring back are thinning, which typically supports Very Good or Good depending on extent.
Here is the scenario we see often. A seller lists a gray cashmere crewneck as Excellent. The buyer opens the package, holds it to a window, and finds three pinprick holes near the hem and a see-through elbow. Return, refund, and a not-as-described case. The seller did not lie. They never ran a light test, and nobody told them that three defects can look like one.
Why moth holes, thinning, and sheen loss get confused
Fine knits hide damage in a flat photo. Cashmere and fine merino have short, soft fibers, and a tight gauge makes a thin patch look like a faint shadow. A moth hole in a fuzzy knit can be hidden by surrounding pile. Sheen loss, where the surface goes dull and flat, can look like thinning even though the yarn is intact.
They are three different defects, and they land in different places on the scale:
| Defect | What you see | Cause | Primary factor |
|---|---|---|---|
| Moth hole | Open gap, cut or missing yarn, often in clusters | Larvae eating fiber | Structural Integrity |
| Thinning | Translucent or flattened patch at elbows, cuffs, underarms | Friction and abrasion | Fabric Condition |
| Sheen loss | Dull, matte, slightly rough surface | Pilling removal, washing, wear | Cosmetic Appearance |
Sorting them matters because a buyer reads "moth" as a contamination risk and "thinning" as wear. Same sweater, very different reaction.
What you need before you start
- A bright, raking light source: a window or a daylight lamp held behind the knit.
- A dark surface and a light surface, to catch holes that blend into the knit color.
- A tape measure for logging hole size and patch dimensions.
- A magnifier or phone macro lens.
Work on a clean, dry sweater. Odor or dirt can confuse the read, so run the Odor & Cleanliness check first.
The light and stretch test, step by step
- Lay the sweater flat under raking light. Sweep light across the surface at a low angle. Note any dull zones (sheen loss) and any dimples or gaps.
- Hold it up to backlight. Put the knit between you and a bright window. Pinpoints of light are holes. A broad, even glow is thinning. Mark each location.
- Inspect cuffs, elbows, underarms, and the hem. Thinning concentrates where friction happens. Moth damage often sits in folds and under collars, where larvae stay undisturbed.
- Stretch the area gently with both hands. Pull about an inch and release. Thinned knit stretches evenly and recovers. A moth-eaten area shows loops that separate, run, or stay open.
- Look for cut yarn ends. Under magnification, moth holes show clean-chewed or frayed ends with missing stitches. Abrasion thinning shows worn but connected fibers.
- Check for secondary signs. Look for tiny casings, webbing, or frass (gritty residue) in seams and folds. If you find them, set the sweater aside and treat it before it touches anything else.
- Measure and log. Record the count and size of holes, and the size of each thin patch. These numbers feed the tier and the disclosure line.
A quick tell between the two
If you can push a pencil tip through the spot without parting yarn, it is thinning. If loops separate and the hole grows, you have a hole, even if it is tiny.
How each defect maps to a tier
These are working ranges, not guarantees. Placement depends on count, location, and whether the damage is stable.
| Finding | Likely tier | Why |
|---|---|---|
| No holes, no thinning, even sheen | Excellent | Clean on all five factors |
| Light sheen loss, minor pilling, no thin zones | Very Good | Cosmetic Appearance only |
| Slight thinning at one elbow or cuff, no holes | Good | Fabric Condition drops, structure intact |
| Visible thinning at multiple points, light shows through | Fair | Fabric Condition clearly weakened |
| One or more moth holes, even small | Fair | Structural Integrity compromised |
| Multiple holes, runs, or active infestation signs | Poor | Damage may spread; wearability limited |
One small, mended hole in a hidden spot can sit at the top of Fair if everything else is strong. Disclose the repair plainly, as you would for any repaired garment.
How the five factors weigh in
Cashmere stresses two factors more than most fabrics. Fabric Condition captures thinning, hand-feel, and fiber loss. A sweater that feels papery or scratchy where it used to feel soft has lost something real. Structural Integrity captures holes, runs, and weak seams. Any open hole lands here and tends to drive the grade.
Cosmetic Appearance covers pilling and sheen loss. These are visible but fixable with a fabric comb, and they rarely drop a sweater past Good alone. Functional Elements matter less on a pullover, but check cuffs and ribbing for lost elasticity. Odor & Cleanliness deserves a second pass: cedar, mothball, or musty smell can be a disclosure item even when the knit is intact.
Write the disclosure line
Buyers of cashmere inspect closely and ask questions. A clear line prevents most of them. Use measurements and locations, not adjectives.
- Thinning: "Light thinning at both elbows, about 2 inches across each, no holes. Shown in photos 6 and 7."
- Moth hole: "Two small holes near left hem, each under 1/8 inch. Photographed against a dark surface."
- Sheen loss: "Slight surface pilling removed with a fabric comb; mild matte patch at cuffs."
Then shoot the evidence: one backlit photo showing light through the thin zone, and one macro shot of each hole beside a ruler. On eBay, a buyer who opens a not-as-described case wins on visible mismatch. A photo that already shows the defect closes the case before it opens. Our photography guide covers the lighting setup in detail.
Common misgrades to avoid
- Calling thinning "like new." If light passes through, the yarn has lost mass. That is not Excellent.
- Calling a hole "a snag." A snag pulls a loop. A hole has missing fiber. Buyers know the difference.
- Skipping the stretch. A sweater can pass a visual check and still run when handled.
- Ignoring where you store it. A sweater with moth damage can infect others. Bag and freeze it for a week before it goes near your inventory.
Grade one cashmere sweater and see the report
Pull one cashmere or fine wool sweater from your stock, run the backlight and stretch steps, and write down what you find. Then grade the same piece in GradeThread and compare. You get a 1.0–10.0 grade, a report across the five factors, and a certificate buyers can verify. One sweater is enough to see whether your calls match.