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An Underbase with a Punch

(September 2006) posted on Mon Sep 18, 2006

Explore how creative uses of underbases can produce some knockout designs.

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By Thomas Trimingham

The downside comes when you print a bright red and don't want it to turn pinkor when you try to match a Pantone color. When the puff underbase expands, it spreads out the pigments in the top layer of ink and tends to lighten that ink noticeably. In our red example, it'd be beneficial to use a red puff underneath for just the red areas, in addition to a white puff, to maintain the color purity of the top red hue (as long as you have enough flashes to do it).

Resist the temptation to just throw a puff ink under your print and start the press running. Wait until you've tested the ink and the process and have determined what the final results will be with the style of ink and art that you're using. A good test file (Figure 2) consists of a variety of shapes in different sizes and distances from each other. Just print the file onto a scrap shirt to see how much it puffs up and how smooth the surface is. A rule of thumb when using puff inks as underbases is to not have large, solid areas and to break up the underprint as much as possible to prevent it from becoming too heavy, which could buckle the shirt fabric. A large, puffed area on a shirt also will often crack after several washes.

Redesigning the art for the process

I reviewed the test file and determined the best ink mix for the underbase and then proceeded to redesign the file to utilize this process in the best manner. The object of redesigning the file in Photoshop was to create a metallic look in the print that included lettering, bolts, fist, and borders that looked dimensional (Figure 3).

One of the things I discovered after using this process several times is that any large areas that you underbase with puff should have significant color variation to them. A large, flat area of color that has a puff underbase will show all of the imperfections of the puff underbase loud and clear. The best result comes from using a couple of graduated fills or overlapping colors that will help hide imperfections in the halftone dots. The little bubble holes and bumps blend into the halftone patterns and don't show nearly as much.


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