2. What is the difference between "water" and "alcohol" plates, and which is better ?

3. Can I make my own plates ?

4. How do I choose between polymer plates and steel plates ?

5. Can I reclaim a plate (erase the old image and replace it with a new one) ?

6. I make my own polymer plates. How do I know if they are right ?

1. Question : What do I use to clean a plate ?

Answer : for polymer plates, use screen wash, ink thinner or lacquer thinner. NEVER USE THE DEVELOPING CHEMISTRY TO CLEAN A PLATE, even if it is a weak solution. Steel plates should be cleaned in the same way. Additionally, steel plates which will go unused for an extended period of time should be coated with a light oil to prevent oxidation.

2. Question : what is the difference between "water" and "alcohol" plates, and which is better ?

Answer : "water" and "alcohol" refer to the solution in which the exposed photopolymer plates are processed. Due to environmental pressures, manufacturers of plate materials have been making a concerted effort to develop effective water-based systems. At this point, Printex maintains that the alcohol-based plates still offer better image quality and durability. However, there are some alcohol-based inks which will dissolve alcohol-based plates. In this case, the advantage of water-based plates becomes obvious.

3. Question : can I make my own plates ?

Answer : for photopolymer plates, the answer is yes. Printex offers our UVAC-600 photopolymer plate exposure unit, and related supplies for end-user plate making. The user must provide some other items, including a source of film positive for plate exposure. Manufacturing steel plates requires corrosives and other nasty chemicals. For liability reasons, Printex does not offer a do-it-yourself steel plate system.

4. Question : how do I choose between polymer plates and steel plates ?

Answer : service life is the primary factor in determining which type of plate to use. Steel plates last much longer than their photopolymer counterparts, and also tend to be more expensive. A steel plate is a good choice for an image which you know will be used indefinitely and repeatedly. Polymer plates are excellent for short-run work, where frequent image changes are common.

5. Question : can I reclaim a plate (erase the old image and replace it with a new one) ?

Answer : for polymer plates, the answer is no. Once an image has been exposed and processed on the plate it is fixed and cannot be changed. Thick tool steel plates can sometimes be lapped to remove the old image, then re-etched with a new one, but the hardness and service life of the plate will suffer dramatically.

6. Question : I make my own polymer plates. How do I know if they are right ?

Answer : 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 of approximately .0015". 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.