What basic indicators of textile silicone determine the quality?

What basic indicators of textile silicone determine the quality?
Colloid purity and stability
No impurities: High-quality silicone should be translucent or transparent, without visible particles, bubbles or yellowing, and the texture should be uniform and fine after mixing.
Chemical stability: Strong aging resistance, no curing, stratification or significant change in viscosity after long-term storage (such as 6-12 months).
Environmental certification: Passed RoHS, FDA and other certifications (according to the application scenario requirements), special attention should be paid when it is suitable for food contact, medical and other scenarios.
Viscosity and thixotropy
Moderate viscosity: The viscosity of screen printing silicone is usually 5000-20000 cps (adjustable according to the mesh number of the screen), too thin is easy to penetrate ink, too thick is easy to block the screen.
Good thixotropy: It becomes thinner due to shear force during printing, and it is easy to leak ink; the viscosity is quickly restored after shearing is stopped, and the edges are clear and not blurred.