# Gauge, Modulus, and Reduction on Cast or Dipped Film
Human page: https://retifist.com/literature-reviews/liquid-gauge-modulus-reduction
## Executive summary
On dipped, cast, or spread film, fit is three knobs. Gauge is finished-wall thickness. Modulus is compound stiffness at a stated stretch. Reduction is pattern shrink versus body measurements.
Fillers and graft modifiers raise modulus. A thicker wall of the same compound is a different move from a stiffer mix, and both are different from a smaller draft. Use when a cast piece feels boardy, bags after wear, or a thicker wall is treated as a tighter pattern.
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## Gauge is formed-film thickness
Gauge is dry-film thickness (mm or mil). You form the wall. Forming levers live in [Home-cast latex film](/literature-reviews/liquid-home-cast-film) and [Coagulant dipping for wearable thickness](/literature-reviews/liquid-coagulant-dipping-wearable-thickness).
At unchanged modulus, a thicker wall of the same compound is harder to bend and takes more force to reach the same body stretch. Gauge geometry, not a new MPa number.
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## Modulus is set in the compound
Modulus is stress at fixed extension (MPa at 300%, psi at 500%). Higher modulus is boardier at the same gauge. Set this in the liquid before dip or pour.
**Mineral clay.** DIXIE clay 0 → 50 phr (CR handbook series) drops tensile **3100 → 1500 psi** while stress at 500% rises **500 → 1100 psi**.[^1]
**High-styrene SBR polymeric filler.** At 20 phr in an NR film series: 300% modulus **0.90 → 2.76 MPa**, tear **1769 N/cm**, set **6 → 30%**. Handbook flags the modulus rise as a disadvantage for some latex uses.[^2]
**MG graft latex.** Methyl-methacrylate-graft NR raises modulus, hardness, and tear in NR blends. Industrial uses include tubing and glove puncture resistance. MG 30 / MG 49 graft levels; moderate graft blended with NR for films thicker than about **0.5 mm** without cracking.[^3]
Plant-film examples, not home mixing cards. Dispersion and loading: [Pigment and filler compounding for liquid latex](/literature-reviews/liquid-pigment-filler-decks).
Elastomeric film must stretch at least **2×** and recover. Fit needs strain margin inside that capability.[^4]
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## Reduction is pattern geometry
Reduction is negative ease: flat pieces drawn smaller than body measurements so the garment must stretch to close. Geometry, not a phr number.
A higher-modulus compound makes the same reduction feel tighter (more force to the same stretch). High set is less elastic recovery: a snug draft can slump after wear.[^2]
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## Decision cues
- Build thickness with forming levers when the wall is too thin or too thick.
- Raise or lower modulus in the compound when gauge is right but hand is wrong. Clay and high-styrene SBR stiffen. Watch set if the piece must snap back.
- Change the pattern outline for a different negative ease.
- Bagging after wear often traces to set or aging, not wall thickness. [Liquid latex aging, storage, and care](/literature-reviews/liquid-aging-storage-and-care).
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## Endnotes
[^1]: Vanderbilt Latex Handbook — DIXIE clay filler series (CR compound example); tensile down, stress at 500% up.
[^2]: Polymer Latices Vol 3 — Application of Latices — high-styrene SBR polymeric filler in NR (handbook Table 16.12 series).
[^3]: Vanderbilt Latex Handbook — MG latex summary; methyl-methacrylate-graft NR; modulus / hardness / tear; MG 30 / MG 49; moderate-graft NR blend for >0.5 mm crack-free films.
[^4]: Vanderbilt Latex Handbook — elastomeric film stretch-and-recover criterion (≥2×).
Deep dive: High-styrene SBR polymeric filler
NR film series; 0 and 20 phr high-styrene SBR. Plant example.[^2]
| phr filler | Modulus 300% (MPa) | Tear (N/cm) | Set (%) |
| --- | --- | --- | --- |
| 0 | 0.90 | 1156 | 6 |
| 20 | 2.76 | 1769 | 30 |
Deep dive: Mineral clay direction
CR 750 + DIXIE clay 0 / 25 / 50 phr (industrial cure 60 min at 127 °C): tensile **3100 / 1800 / 1500 psi**; stress at 500% **500 / 600 / 1100 psi**.[^1] Direction (stiffer, weaker in tension) is the teaching point.
Deep dive: MG graft latex
MG 30 / MG 49 graft levels adjust modulus and tear. Blend with NR; moderate graft for films thicker than about 0.5 mm without cracking.[^3] Industrial tubing / glove puncture-resistance class.