# ES1 FABRIC / MATERIAL SPEC v1

Status: DEVELOPMENT SPEC FOR SAMPLE BUILD. Lock after physical sew-out and wash testing.

## Primary fabric recommendation

Exterior and face-contact fabric: 100% mulberry silk charmeuse, Grade 6A target, 22 momme target (about 95 g/m2), long-fibre silk, soft lustre, no abrasive finish.

Why 22 momme: it is a proven premium sleep-mask weight with a useful balance of drape, opacity, durability and skin feel. Current premium competitors including Slip and Drowsy specify 22 momme mulberry silk.

Colour/dye target: non-toxic dye system; supplier should provide OEKO-TEX Standard 100 or equivalent skin-contact textile evidence where available. Require lab dips before bulk dye approval.

## Construction recommendation

Exterior shell: 22 momme silk, bias or near-bias during prototype forming so it can follow the convex foam surface without hard darts. Stabilise seam perimeter before final topstitching.

Face-contact lining: 22 momme silk, true-bias prototype cut. The eye-cavity areas must be physically formed into the foam recesses rather than allowed to bridge flat across them.

Preferred production path: mechanically form/tension the lining over the cavity geometry, then secure at perimeter / approved hidden construction points. Do not place a hard adhesive ridge where it can contact the face.

If bonding is required, supplier must propose a silk-safe, low-VOC, flexible adhesive/lamination process and provide an adhesion/handfeel/colourfastness sample before approval.
## Strap textile

Use the same 22 momme silk on the visible strap surface for colour consistency. Internal strap structure may use elastic, low-profile hook-and-loop and a soft padding/interlining; these internal materials must not create a hard edge at the temple.

Working finished strap width: 38 mm. Final width, elastic percentage and hook/loop overlap remain sample-gated.

## Alternatives to test

A. 19 momme silk: lighter and easier to form, but less robust and less premium-feeling. Prototype-only comparison.

B. 30 momme silk: heavier and durable, but more difficult to conform around the cavities and likely unnecessary for this product.

C. Silk/elastane lining: mechanically easier to form into deep eye cavities, but it changes a strict '100% silk' material claim. Use only if the 100% silk lining cannot pass the cavity-forming test.

## Supplier tests required before production release

1. Fibre-content verification.
2. Momme / GSM verification.
3. Colourfastness to water, perspiration and dry/wet rubbing.
4. Dimensional change after the intended care cycle.
5. Seam slippage / seam strength on the selected stitch construction.
6. Abrasion / pilling and snag review.
7. Dye transfer onto light pillowcase fabric.
8. Skin-contact finish and odour review.
9. Adhesive compatibility test if any lamination is used.
10. Sewn sample after at least one wash/care cycle before bulk approval.

Do not compensate pattern dimensions for silk shrinkage until measured shrinkage is known from the actual supplier fabric and care method.