1. Shorten exposure time and solve the problem of blunt transition dots
The author once printed a drug label with a transition screen effect. The client requested that the effect of the transition screen be softer, but the transition dots printed by the proofing printing were relatively stiff and could not meet the needs of the customer. After observation, the author found that the minimum dots in the transition screen are about 3%, which is basically the minimum dots that can be exposed by the letterpress resin plate. If the dots are reduced and the film is re-produced, the small dots are likely to be lost after printing, so this problem cannot be solved by re-producing the film. Since the letterpress resin plate is imaged by light curing, the author asked the plate maker to shorten the exposure time, so that the dots exposed on the resin plate are smaller than those exposed by the normal exposure time. After proofing again, the transition network effect becomes Soft, the customer is very happy with it, and we successfully fulfilled this order.
2. Back exposure solves the problem of large-area transition network drop points
Anyone who is familiar with the flexo plate making process of self-adhesive labels knows that there is a back exposure process in the flexo plate making process, the purpose of which is to make the image and text more firmly combined with the plate base. But many people may not know that this back exposure process can also be applied to the plate making process of letterpress resin plates. In daily production, we often encounter jobs with large-area flat screens or large-area transition screens. During the printing process, small dots are often lost due to poor exposure time, especially when making large areas. The printing plate of the transition screen has more stringent requirements on the exposure time: if the time is too long, the plate may be pasted, and if the time is too short, the dots may be dropped. At this time, the back exposure process can be used in plate making, that is, the back of the resin plate is exposed, and the time of back exposure should be flexibly controlled according to different jobs. Practice has proved that the resin plate after back exposure treatment is not easy to drop the dots when it is exposed to a large area of transition dots.
