The four silks compared on eight physical properties. One row in this table decides more than any other: non-broken filament length. Muga’s 150–250 m of continuous filament is what makes reeling possible; eri’s few centimetres do not, which is why eri is spun and muga is reeled, and why every downstream process differs.
Cross-section and lustre
Cross-sections are shown schematically, turning so the depth of the section is visible; hovering pauses one. Shape, not chemistry, is what separates a bright sheen from a deep glow — and it is also why muga’s golden colour deepens rather than fades with washing.
Muga, eri, mulberry and tasar
| Property | मूगा | एरी | शहतूत | तसर |
|---|---|---|---|---|
| Total filament length (m) | 600 – 800 | 400 – 500 | 1,200 – 1,600 | 750 – 900 |
| Non-broken filament length (m) | 150 – 250 | 0.05 – 2.0 | 700 – 800 | 100 – 250 |
| Fineness (denier) | 4 – 7 | 3 – 4 | 2 – 3 | 8 – 12 |
| Density (g/cm³) | 1.30 | 1.30 | 1.34 | 1.31 |
| Fibroin / sericin (%) | 80–86 / 12–16 | 82–88 / 11–13 | 66–72 / 25–32 | 78–85 / 14–17 |
| Tenacity (gf/den) | 4.2 | 3.1 | 4.5 | 3.9 |
| Elongation at break (%) | 30 | 22 | 19 | 28 |
| Toughness (gf/den) | 1.1 | 0.5 | 0.6 | 0.9 |
- Non-broken filament length decides the route. Muga’s 150–250 m of continuous filament makes reeling possible; eri’s few centimetres do not.
- Muga is the toughest of the four, combining high tenacity with 30 % elongation — roughly double the toughness of mulberry.
- Low sericin means low degumming loss: 11–16 % in muga and eri against 25–32 % in mulberry.
- Cross-section drives lustre. Mulberry is triangular; muga and tasar are elongated rectangular or wedge-shaped with a larger area, giving a deep glow rather than a sharp sheen.
- Muga absorbs about 85 % of incident ultraviolet and its natural golden colour deepens rather than fades with washing.
- Eri behaves like a wool — dense, warm in winter, cool in summer, and readily blended.
Values vary with ecorace, season, host plant and cocoon layer; single-fibre denier falls and tenacity rises from the outer floss to the inner pelade layer.