Incandescent and flood lights don't emit enough of these wavelengths to be considered serious production tools. With few exceptions, all stencil materials can be used with exposure units, but you may see differences in time and image quality, depending on the light emitted. Lamp intensity doesn't refer to how bright the light appears to the human eye. After all, UV isn't even visible. Intensity is measured as the amount of actinic light reaching the screen.
Lamps degrade and can outlive their usefulness before they burn out.
For example, when you double the distance, you quadruple the exposure time to compensate for the light intensity loss at the vacuum frame. Conversely, when you halve the distance, you divide the original exposure time by four. Type of emulsion and thickness of the coating Characteristics such as photographic speed and resolution capability will affect exposure times. Stencil materials are designed to do some things well, but no one product excels in all areas. Stencil thickness influences depth of cure, just as ink thickness affects drying or curing time.