Question 1: Both are fabric-backed addition-cure coating silicones — what actually separates them?

Answer: One sentence: silicone leather rubber builds a continuous film that is the material; screen-printing silicone deposits raised, bonded patterns that decorate and grip a textile that already exists.

MY LSR 3221/3271 coats substrate cloth layer-by-layer (base/mid/top) to produce silicone leather used as the finished surface itself. MY LSR 3140 is scraped through a mesh screen to form floral belts, woven labels, anti-slip dots, and 3D texture on cotton/polyester/nylon fabrics. Selection rule: you're manufacturing the leather → 3221/3271; you're decorating or adding grip to fabric → 3140.

Question 2: How do the specs and processing differ in practice? Can they substitute for each other?

Answer: Let's look scenario by scenario (based on measured parameters of commercially available grades):

Conclusion: They are process-specific grades, not interchangeable. Running screen ink as a full leather coat gives you a stiff, expensive film with poor release handling; running leather coating rubber through a screen floods the mesh — its viscosity was built for flowing flat, not standing proud. Practical guidance: ① if your product is bags, shoes, apparel panels, or baby-mat surfaces, specify the 3221 base-coat route and tune coat count, then add hand-feel oil for retail-grade touch; ② if your product is decorative/functional patterns on fabric — flower belts, anti-slip pads, woven labels, silicone badges — 3140 is purpose-built, and note color paste goes into component B (the one without platinum) to avoid catalyst poisoning; ③ for hybrid designs (printed pattern on silicone leather), bench-test interlayer adhesion first, since the topcoat's release treatment is designed to prevent sticking. Verify wash-fastness, crocking, and cure-through on your actual fabric and mesh count before production changeover.

Methyl silicone Gum, plz check MY 3101