16 December 2009

Letterpress, Not Screen Print

Despite the many print jobs I've had in the past few weeks, I still managed to design and print two new holiday cards. Well, I cheated a little on the design, and took one of the motifs from my first design, enlarged it, added to it a little, and printed it on its own.

I started by drawing the images by hand, then I scanned them and opened the files in Illustrator. I used live trace to convert the images to vectors, which generally print much better than, say Photoshop files. Once I was happy with the designs, I had to separate the colours (which was easy since I only used two colours in one card and one for the other, so all I had to do was select the relevant parts and drag them to a new file), then convert everything to registration black.

Registration black--that is, black that will be printed with CM and Y as well as K, and not just the black ink cartridge--is necessary to make the negative dense enough to block light. I send my files off to a pre-press guy, who sends me back a negative. I cut the pieces for the different plates apart and then use a platemaker to create the images on polymer. After washing with soft brushes to remove the unexposed polymer, the plates are dried and then cured in the sun. I leave them to cure for at least 24 hours before printing.

I tried to print the single reindeer card with a split fountain (there's no actual ink fountain on the press, but it's basically using two--or more--colours on the same press; in litho class we called it a "rainbow roll"), and you can see from the photo that it looks great on the rollers and even on the plate. Look at the image of all the printed cards, though, and you can see that they dried in a solid grey-blue. I'm still not sure quite why that happened.

I also printed a two-colour card with 3 reindeer, but neglected to photograph it in process.

Interestingly, everyone who saw the reindeer card at the craft fair thought it was either a screenprint or a die-cut until I showed them how the relief printing created an embossed effect where the white deer shape is raised above the surface because the coloured areas were pressed into the paper with so much pressure. I guess I have to learn how to design letterpress images that look like letterpress.

Photo credits: Top = polymer plates for holiday cards and 2010 calendar. Second = two inks at once on the press and the plate. Third = a whole pile of reindeer cards, printed and drying. Bottom = my booth at the Halifax Crafter's Christmas Fair. A little crowded, but each time it looks a little better. All photos by Niko Silvester, taken with an iPhone.

No comments: