One of the most important steps in the screen printing process is the creation of film positives. It can be easy to overlook the details of this step due to the various types of film available today.
The best film positives are absolutely opaque. However, the basic purpose of a film positive is to block UV light during the exposure process from curing the emulsion coated on your screen. In this weeks blog we’re discussing the most widely used types of film and a few less than ideal solutions that are budget and beginner friendly.
Inkjet Films can be printed in most of your standard inkjet printers and are made from plastic. These will typically work better with dye-based inks rather than pigment-based inks used in most household printers today. Inkjet films are available in waterproof film as well as less expensive non-waterproof. To make sure the film positive is dense enough, often RIP software will need to be used. Many RIP software’s will include black ink conversion kits so that every printhead on your printer will print dye-based black ink which helps produce the best film positives.
Laser Films are also made of clear plastic but are less popular since density and coverage are very difficult to control. Your toner can only be managed so much by your printers settings, and the age of the toner cartridge may also have negative effects on film positives. Because of the heat produced by the fuser, distortion may become a problem in larger images when using laser films.
Laser Vellum is very similar to laser film in that it has much of the same issues, but is a transparent paper product. Shrinkage and wrinkling in the fuser can also occur when using laser vellum which therefore can be a problem registering on- press with complex, multi-color jobs.
Thermal Films can produce very opaque, high quality and dense film positives of your artwork and is much more expensive than inkjet or laser films. These are produced through a thermal printer and are made of clear plastic as well.
And now for a few budget and beginner friendly bet less than ideal solutions:
Copier Transparencies must be the worst of any film positive used for screen printing, but it can be done. Usually they must be doubled up to get the opacity needed for screen making. Although readily available, they are very low in resolution and density. These are made of clear plastic.
Clear Acetate using Plotter Cut Vinyl is a do-it-yourself solution to making film positives but can produce very opaque results. This is a great way to get rid of any vinyl you have lying around if you also make signs or banners. Application is simple, just apply the vinyl to your acetate film and you’re good to go, as most colors of vinyl will block enough UV light. Darker colors will give you the best results. This solution works best if you have simple one-color designs.
We hope you found this quick guide to different types of film helpful in determining what solution works best for you! Check out our film output supplies here.