Can I get Solid coverage on high-touch stock?
Solids
Letterpress is at its best with line art and typographic elements. It requires extra effort and often additional cost to make sure that solid areas - over 3/16 inch - are seen as solids. Smooth surface papers help quite a lot with this. We also will make use of fine-arts printmaking techniques such as dampening the paper to produce a perfect ink-film. However, for reverses, and solid coverage we often recommend the use of offset lithography which we offer through our local commercial print partners.
Another option is the use of duplexed stock, where two sheets of different colors (often white with another color) are bonded into one heavy sheet in a special process. Our Bugra colors are available in any combination of 22 colors, as double, triple and even quad weight sheets, with no minimum.
We can also have any Bugra color bonded to any other sheet. Non-standard combinations can get pricey, though, often doubling or tripling the cost of the stock. Some minimum and setup charges apply.
"Double-bump"
For smaller areas such as logos on business cards, we can take advantage of the amazing perfect registration of the Heidelberg Windmill press to "double-bump" the impression. We will run the cards once through the press printing the entire image, then strip the plate of fine detailed line and type matter, leaving the heaviest image in place. The plate is then returned to the press and the job run through again. The initial impression has flattened the fibers in the stock, so that the second impression can lay a very smooth solid ink film.
Without the additional hit, the texture of the paper shows through more, which gives the old-time letterpress look. Not a bad thing, but not at all like the density of a solid on the screen. Smoother papers, of course, require less ink and impression to fill the surface.
And some fine printmaking papers are microstructurally more receptive to the ink on the first impression, and give a better density without double-hit.
Two very lovely papers, the Italian Arturo 600gsm and the German Copperplate Etching (300 or 600) are recommended for this reason.
It's always a balance between sharp detail and density of the ink film.
If we lay enough ink on the sheet to make it solid in one pass, the details can get filled in, edges are mushy, etc.
Even with the 'double-bump' or second pass through, a solid black as in some logos or reverses will inevitably show variation in density from card to card. Lighter colors will vary somewhat in intensity.
The presses themselves are 50-60 years old at this time. Variations in feeding the press sheets will mean that if occasionally a piece mis-feeds, or doesn't feed, the inking rollers will double-ink the plate, creating a heavier inking on the next one or two cards.
While the modern eye, which is accustomed to high-contrast digital imaging, on screen or on high-gloss surfaces, sees this as a good thing, it's not in the nature of good letterpress printing to put so much ink down in one pass.
That's why we offer the double-hit. But even then there is variation. The alternative is to load so much ink on the plate that all subtlety and sharpness is lost. This is a particular problem when there's a reverse out of the black with fine detail. .
In any case, we've been working hard to find the perfect balance between density and crisp printing, mixing custom inks, adjusting rollers and finding papers which respond most perfectly to the letterpress impression.