Knowledge of photographic graphics

Exposure: put the ps plate coated with photosensitive layer on the printer workbench, put the negative film well, and expose the negative film twice by main light and light transmission, so that the pattern on the ps plate shows the basic "image" (note: for the exposure conditions of ps plates of various models, it is recommended to use 3kw light source 1 iodine gallium lamp, and the distance between two lamps 1m), and the practice report of graphic cognition. The printing process is automatically controlled, but the following basic details should be paid attention to: 1, the position of teeth or occlusion should meet the technical requirements, and the plate position is generally in the middle. (1) When the printing plate is the same size as the iron plate, it should be noted that the blank county in front of the page should show the crosshairs, and the left and right sides should also show the+lines; (2) If the size of the iron sheet remains, it is necessary to negotiate with the merchant to clarify the blank position of the remaining iron sheet; Customers who have special requirements for spare iron should meet the corresponding standard requirements so as to reserve them when printing; (3) When the size of the printing plate exceeds the size of the iron sheet, it can be exposed first, and then covered with the iron sheet in the original position and exposed again to remove the redundant image. These are special cases. General plates should be made according to the size of iron sheet, which is economical and reasonable and meets the technological requirements.

If 0.23 * 712 * 512/mrt4 tinplate is used for stamping the crown cover, the core size of the plate is 7 12*505mm2, and 1-3mm can be left in front of the plate during printing, and a gap of 4-6mm can be left at the grinding position (in this case,

2. Before starting the power supply of the printer, check whether there are foreign objects such as a ruler and a board trimmer on the workbench, otherwise it will blow up the glass frame of the printer.

3. Should the 3.ps version be put in place? /font Note that the vacuum outlet on the side of the machine cannot be covered.

4. Setting of exposure time: The main exposure time is usually 90- 100s, and the auxiliary light is 15-20s. (1) The exposure time is too long, the pattern on ps plate is fragile, easy to fall off, and some meshes are lost, and the printing plate has poor printing resistance; (2) If the exposure time is not enough, the pattern will be very light and empty. (3) When the performance of the lamp tube deteriorates for a long time, the exposure time can be appropriately extended or the lamp tube can be replaced. The internship report is a graphic cognition internship report.

5, ps version: Be careful not to bend to make "dead marks", otherwise it is easy to appear blurred patterns, ink holes and poor coloring when printing.

After development, the exposed ps plate will be laid flat in the developing tank, so that the developer will be fully wetted by it. After about 1 min, the dissolved coating on the washing table will be taken out and an "image" will be displayed.

Pay attention to the following points when developing:

1. Ratio of developer to water. Generally, when buying ps version, a certain amount of developer will be attached. The ratio of developer to water should be slightly greater than or equal to the ratio of original concentrated solution, especially in summer. Too high concentration of developer will remove effective dots, and insufficient concentration will prolong the development time, make the layout dirty and affect the durability of ps plate.

2. Control of development time. In general, it is appropriate to put ps plate in the developing tank 1 min (obvious bubbles will appear in the plate during development). If the development time is too long, the "image" on the page will be removed, and if the development time is not enough, the page will become dirty.

3. If there are extra spots and images on the developed page, you can remove them with the correction paste and then rinse them with clean water (when revising, you can dip a proper amount of correction paste with a brush and gently smear it on the extra images or spots, then stop for a minute and rinse them with water).

4. Development temperature. Suitable for room temperature (23+2), too high room temperature will make the plate dot decrease; If the temperature is too low, the developmental ability will decrease.

5, development must be carried out in the dark smothering, avoid natural light.