Hello Vanderblog Friends,
I’m hoping someone can help me solve a problem I’ve been having with ink being where it’s not supposed to be.
The piece I’m printing has two lines on which I’m getting flecks of errant ink. The problem occurs no matter how much ink I have on the rollers, and the ink even shows up when I run the paper through on trip. These two lines are handset brand-new 12-point ATF Caslon Italic. This problem occurs only on these two lines. The rest of the piece, in 18-point Bulfinch, looks fine. These two lines fall an inch and a half from the bottom of an 8 ½ by 11 inch sheet of Epson Velvet Fine Art paper (19 mil). I’m using press points. The press is a Vandercook No. 4. A close-up of the photo is available on Flickr: http://www.flickr.com/photos/lunadabayletterpress/4633627048/.
I’d appreciate any suggestions you can offer.
That is a typical Vandercook impression slur (that is, on a press without frisket or tapes), such as is found at the tail of the sheet. The sheet is not controlled as it would be on a real cylinder press (there is no cylinder brush) and the sheet fingers are not enough to keep the tail of the sheet from sliding or slapping, whether on or off impression. In addition to slur, you can have a lengthened form, that is the tail element printing lower on the sheet than the form actually measures. In your case the sheet seems to slap then drop so the impression is noticeably lower than the slur. This can be worse with a traditional form of metal type and furniture because the sheet can sag into the open areas of the form. With photopolymer plates on large bases, the sheet is supported by the base even in the open areas.
On an oversize sheet, bearers will help, or the use of high furniture in the open areas. In a bad case, I will build up pieces of binder’s board over furniture as a sheet support, taking care that it does not ink.
Hi Barbara, I have had paper “slapping” issues in the past and have thin strips of compressible foam similar to the ejecting rubber used in steel rule die making, only less dense. Weather stripping is ideal as it has pressure sensitive adhesive on one side and comes in various thicknesses, widths and densities. By placing it on your lockup perpendicular (if possible) to the cylinder it will hold the paper against the cylinder and compress out of the way when impression is engaged. This technique has allowed me to maintain a good production rate without compromising quality.
Secondly it is important to print with the grain of the paper parallel to the cylinder if possible (but you probablly know that)
Best of luck – Steve
Sorry if this is obvious, but I always try to use a larger press sheet if possible, even for the smallest work, and work-and-turn to use it economically. I think these cylinders want a large sheet wrapped around them to do good work. Every once in awhile i see a vandercook operator trying to print a business card on, well, a business card…
Thanks for your thoughts, Gerald — all good points to keep in mind. I’m assuming the type heights were okay, since the Caslon was a new-old-stock ATF casting and the Bulfinch was cast by the Dale Guild. The packing had been redone fresh, as you suggested.
I think what was happening is that the tail end of the paper was not conforming to the cylinder all the way around, as you also suggested. It was slapping against the bottom of the form, even on trip, and picked up bits of ink from the two lines that were there near the bottom.
What I did was stick some light-tack, double-stick tape to the Mylar draw sheet, just below where the the two problem lines would fall. This fixed the problem. I had to change the tape about every 10 prints because it lost its tack, but one is never really “in production” with a Vandercook so that was not a problem.
There are a number of things that could be wrong here, but I’m not sure the ink is one of them.
If you are using press points you are aware of at least one possible and likely problem. Most often just a good hold down on the cylinder and a last second stretch to the paper will suffice.
The fact that you experience printing on trip though is more disturbing.
A possibility is that the Caslon is not correctly cast to type high. Or at least is not the same height as the Bulfinch. This is often an over looked problem. From foundry to foundry, casting technique to casting technique, type height varies. And the output of the cottage craft industry that has arisen with the demise of the foundries is a bit iffy. Type height even varies on roller height gauges. Quite a bit actually.
Another problem could be your press packing. It is best to pull it and replace on a per job basis. Or at the very least inspect it for over-packing, matrixing (from deep impression), or remnant (hidden) makeready from a previous project.
This is all assuming there is nothing mechanically out of whack with the press itself.