When coating your own screens with direct liquid emulsions, it is helpful to know what problems can arise and what can be done to solve those problems. Let's take a quick look at some common problems related to emulsions and things to check to correct these problems.

Pinholes - We all know that these pesky buggers are a pain to deal with. Dirt and dust can be one of the causes, so it is important to keep all areas and equipment clean. Improper mixing and coating of emulsion, improper mesh preparation, and underexposing your screen are a few more things to check.

Poor definition or rough edges - Look at your mesh count and use dyed mesh, make sure you coat properly and wash out well. During exposure, check your vacuum to ensure correct contact.

Stencil softness - Some culprits include humidity, underexposure, improper mixing of sensitizer, old emulsion, or the positives.

Hazy areas - Check the positive and the vacuum. Light scattering, as well as improper exposure and washout procedures should be considered.

Washout problems - Details wash away due to underexposure, improper mesh preparation, sensitizer mixing, old or wet emulsion, non-uniform coating, or excessive humidity. Details remain closed due to pre-exposure, overexposure, light source and positive issues, as well as old coated screens.