Exposing a Screen vs. Imaging a Screen: Complete emulsion exposure versus obtaining an image on the screen provides two very different results during production. Let’s start at the beginning to see how this difference is often the difference between achieving optimum press performance and struggling to achieve hourly production goals.
Screen exposure is often the most misunderstood area in the screen room. This is simple right? Just expose the screen, dry it, block it out and print it right? First an analogy: Let’s say you need to drive 500 miles today to make it to an important sales meeting. Do you just go to the gas station and put 20 dollars in the tank? The car will run, it will travel quite a distance on 20 dollars, but will it make it the full 500 miles? Typically, almost every screen room exposes a screen using the 20 dollar example. Give it enough light to create an image that doesn’t wash off in development, dry it, and send it on to production where the production manager expects it to last through a long discharge or high solids acrylic print run. The problem is the production manager is unaware the screen maker never filled up the emulsion ‘tank’ with enough light to make the entire journey.
Strong Opaque Film or CTS Imagery allows for maximum exposure times that produce strong screens. Owners will buy brand new screen exposure lamps without considering if the model they choose will expose screens well for all ink systems, then try out every emulsion possible, and yet often suffer through countless screen failures during production. Why? The screen maker simply cuts corners based on past experience that underexposing the emulsion will help develop finer details better. In today’s screen printing rooms the variety of artwork that a shop produces can range from solid athletic style art to very detailed index and simulated process prints that test the limits of your screen room and the resolution capabilities of your emulsion. Click here to continue reading the article: Image vs. Exposure