Excessive heat can prematurely cure a stencil. Follow proper drying instructions.
Pre-exposed
Use under subdued or properly filtered lighting.
Do not allow sunlight into work area.
Overexposure on vellum
Vellum positives have poor black density; overexposing will allow enough light source to pass through the image area and cure the photoemulsion. Use a toner darkener or reduce exposure times through testing.
