UV Screen Printing-Part 10: Pre-press for UV Screen Printing

摘要

Colour separation: The control of ink deposit thickness is especially important when process printing with UV ink. As well as affecting the curing process, an excessive ink deposit will compromise print quality in the following ways: 1. Smearing, or 'gaining', of the halftone dots, reducing the definition of the image, affecting colours and creating tonal jumps; 2. impaired lay down of the final colour - successive thick ink deposits may prevent all of the ink printed through the final screen from reaching the substrate; 3. revealing unwanted grey tones within darker colours as a result of even slight misregistration in areas where there is a large deposit of cyan, magenta and yellow; 4. increasing dot gain with the subsequent loss of shadow details; and 5. giving prints a 'Braille-like' appearance, or variations in gloss from midtones to shadows. Figure 9.6 shows how an excessive ink deposit can impair the lay down of the final colour.