Dragon advertising design printing company printing: color pages, pictures, stickers, static stickers, business cards, disposable cups, woven bags, knife flag, water flag, advertising tents, handbags, single, envelopes, mouse pads, out of paper, packaging, printing, photo, playing cards, advertising fan, exhibition stands, desk calendars, membership cards. Tel: 0371-56612733 13014633725 (Geng) QQ175333004 7213325 151312546; black level density is 3.5 or more. 3, Exposure: back exposure and main exposure: ① back exposure: photopolymer plates up support membrane protective film down tile in the drawer exposure accept exposure. Ultraviolet light of the photosensitive adhesive layer is cured through the support film. The purpose is to establish a solid substrate, but also can control the depth of washout, strengthen the support film and a photosensitive resin layer adhesion. Back exposure time is determined based on the substrate thickness. ② main exposure: photopolymer plate support film down, the protective film facing up. Tiled exposure drawer, the protective film in a row once torn, and then attached to the film surface film with photopolymer plate above the vacuum membrane flat cap on film (non-film with surface), vacuum, so that the photosensitive film the resin layer bonded tightly. Vacuum ultraviolet rays through the transparent part of the film and film to make the plate photosensitive part polymerization curing. Main exposure duration by the media type and intensity of the light source is determined. Photo exposure time is too short make the slope is too straight, curved lines, small print, dots partially washed away, whereas the exposure time is too long will be deposited version, illegible. If there is a plate on the same large, small print, coarse, fine lines, depending on the circumstances were covered with black film exposure, a small part of it will not be lost due to wash, to ensure the printing quality. 4. Rinse: Some wash will not dissolve the photosensitive, photopolymerizable relief reservations. Washout length of time stamped according to the plate thickness and depth of the decision, wash version too short, will leave on the plate did not affect photosensitive resin plate depth of washout time is too long will the media swell, causing the fine portion is deformed or off.