March '17

For the Business of Apparel Decorating

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2 0 1 7 M A R C H P R I N T W E A R || 57 Once your film positives are prepared and your emulsion is dry, it is time to use a pre- registration system. This piece of equipment ensures that your film positive is burned into the same location on each screen using a template while you align the registration marks and stick the film to the screens. The system is best kept in a light-sensitive area, as your screens haven't yet been exposed. EXPOSURE UNITS Exposure units provide coated screens with direct, intense doses of UV light, allowing the design printed on your film positives to be burned onto them. Properly expos- ing screens inhibits screen degradation, and in turn prevents you from having to pause the press in the middle of a job to replace a screen. There are countless types of exposure units, each with varying strengths and features. Sources advise using an exposure unit with a vacuum, since having a tight seal is crucial to getting the best possible exposure. Otherwise, exterior light could get into the unit. Finding the correct amount of light to expose your screens is another aspect of screen making that involves trial and er- ror. Mick Orr, Ikonics, recommends per- forming a "step test," or using an exposure calculator to dial in the correct exposure time. Exposure calculators are thin strips of gradient squares that appear washed out against an exposure unit. These prevent your screens from being over- or underex- posed and allow artwork to be as sharp as possible. WASHOUT AREAS After being burned in the exposure unit, screens must be washed of uncured emul- sion. The basic anatomy of a washout area includes a high-pressure and medium-pres- sure water source, plus a containment area like a washout booth or tank to prevent wa- ter from splashing or leaking out. Sources recommend having stiff brushes, dehazer, and degreaser nearby. Proper ventilation, drainage, and lighting are important for creating the best possible stencil. After setting the film positives aside, the screens are placed upright in the booth or tank. Here, the medium-pressure water breaks down uncured emulsion in the im- age area. Then the pressure is turned up, continued on page 95

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