Awards & Engraving

August '18

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A&E THE GUIDE 2018 • 89 of time. Plus, many types of this resist let you produce many stencils ahead of the time until you get around to blasting the objects. There are a number of requirements to meet to get a good photoresist image, like creating good original artwork printed from your computer, the correct printout substrate to use, the right exposure time, the right washout time, etc. Some of these points I will discuss separately, especially the artwork part, as it is crucial to the whole process. CREATING A PHOTORESIST STENCIL Let's assume that you know how to create the proper artwork and have the original on hand. What are the next steps in creating a photoresist stencil? First, you have to have some basic equipment to process the material: an exposure unit and possibly a washout station (deep sink and spray nozzle) and a dryer (if you are using the washout type of resist). These pieces of equipment are best placed into the above-referenced semi-dark room. By that I mean a windowless room that uses yellow lights, not red lights as in photograph development. Should you choose the dry-processing film, the washout station and the dryer are not required. I will go into a bit more detail about this choice in a moment. The cutting process is completely replaced by exposing the photoresist film to ultraviolet light. That sounds simple enough and it is, providing you follow the processing instructions to a T. In all cases, this means that the printed side of the artwork has to face the dull (emulsion) side of the film, and both have to be inserted into the exposure unit in such a fashion that the artwork backside faces the light source. That may sound confusing, but once you have done this a couple of times, it is not an issue. There are exceptions, like a purple film called UltraPro and a green film called RapidMask. The rub with both of these films is that they do not have an obvious dull side because the emulsion side is covered with a thin layer of plastic. This causes problems for some, but again, after a few tries, you will catch on to how to determine the emulsion side. After the artwork is exposed to the film for a specified time, the artwork is removed and the film is washed out with (prefer- ably) warm water. Wherever the emulsion of the film was covered Sandcarving The most common exposure unit using ultraviolet light is known as the Letralite. It is the economical unit available (around $300) and accommodates a full sheet of photoresist, which measures 10 by 12 inches. Get involved in editorial opportunities for A&E each month! Call Cassie Green at 720.566.7278 or email

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