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1. How do I choose between photopolymer plates and steel plates?
2. What is the difference between "water" and "alcohol" plates, and which is better?
3. Could I make my own plates?
4. I make my own polymer plates. How do I know if they are right?
5. Could I reclaim a plate (erase the old image and replace it with a new one)?
6. What do I use to clean a plate?
1. How do I choose between photopolymer plates and steel plates?
Service life is the primary factor in determining which type of plate to use. Steel plates last into the 100,000 to 1,000,000 and longer life cycles and are more expensive than photopolymer plates. Photopolymer plates have a relative life of 20,000 to 60,000 cycles and cost considerably less than steel plates. A steel plate is a good choice for an image that you know will be used indefinitely and repeatedly. Photopolymer plates are excellent for short-run work, where frequent image changes are common, or for do-it-yourself customers.
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2. What is the difference between "water" and "alcohol" plates, and which is better?
"Water" and "alcohol" refer to the solution in which the exposed photopolymer plates are developed. Due to environmental pressures, manufacturers of plate materials have develop effective water-based systems. The rising cost of shipping and handling alcohol-related developers from the Department of Transportation (DOT) after 9/11 make using alcohol developing plates less and less cost effective.
In earlier times, alcohol plates represented the better products, now this is no longer the case. At this point, Printex G2-73 water developing photopolymer plate material is superior to any other materials carried by Printex or in the marketplace. Plus, there are some alcohol-based inks which will dissolve alcohol-based plates. In this case, the advantage of water-based plates becomes even more obvious.
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3. Could I make my own plates?
For photopolymer plates, the answer is yes. Printex offers our UVAC photopolymer plate exposure units and related supplies for end-user plate making. Printex also offers plate curing ovens, and both inkjet and laser artwork films and chemistry to support end-user plate making in addition to technical training and support. Manufacturing steel plates requires specialized equipment and the use of corrosive chemicals. For these reasons, Printex does not offer a do-it-yourself steel plate system.
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4. I make my own photopolymer plates. How do I know if they are right?
A good plate is characterized by a crisp image area which is uniform in appearance, uniformly clean and smooth non-image areas and an etch depth yielding good ink opacity. Examine your plates for streaks, processing brush marks, voids in the image and "pimples" (high spots) in the image. Also, examine the screen pattern in the image areas of the plate under magnification to ensure that the screen is uniform. If all appears well, the only remaining issue is depth of etch. Try printing with the plate to check the opacity and relative wetness or dryness of the print obtained.
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5. Could I reclaim a plate (erase the old image and replace it with a new one)?
For photopolymer plates, the answer is no. Once an image has been exposed and processed on the plate it is fixed and cannot be changed. Thick steel plates can sometimes be resurfaced to remove the old image, then re-imaged with a new one. Please consult with Customer Service to discuss your application.
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5. What do I use to clean a plate?
For photopolymer plates, use C-Solv, ink thinner or lacquer thinner. NEVER USE THE DEVELOPING CHEMISTRY TO CLEAN A PLATE. Steel plates should be cleaned in the same way. Additionally, steel plates should be coated with a light oil to prevent oxidation.
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