Every platen or lever press has wear on the rails and needs tape on the rails to raise the rollers to the right height. This is whether you use lead type or polymer--although the problem surfaces more frequently on polymer if the roller rails aren't set correctly. You have to build up the rails that the roller trucks travel on so that the rollers just grace the surface of the form. The best way to do this is to add equal layers of masking or strapping tape to each rail. Keep building up the rails in this fashion until whatever you're printing doesn't ink up at all (i.e. bring the rollers up just past the point where the rollers ink the plate). Then take off one layer of tape so that the rollers drop down with minimum contact to the plate. This will keep ink from getting on the backing of the plate and the base, and it will also help make your printing crisper. It's not uncommon to have to add as much as a 1/16"--or sometimes 1/8"--in tape in order to get the rails to the right height. These presses are often 100 years old and have 100 years of wear that you have to overcome. We do not recommend that you adjust your trucks or printing plate/base for this problem. Better printing results from type-high rollers. After you add tape to your rails, we recommend using a roller gauge to perfect the height of your rollers.

Roller gauges are especially indispensable with a platen press. Letterpress rollers need to be positioned just right in order to deposit a thin film of ink onto the surface of the form, without squeezing ink over the edges. A roller gauge will help you accurately measure the height of your rollers so you can produce the crispest printing that your press is capable of. We sell roller gauges, precision ground to type high, which are also very fashionable.

When your rollers are positioned correctly, your printing will look beautifully crisp. This is because correctly positioned rollers deposit a thin film of ink onto the surface of your printing plate (without squeezing ink over the plate’s edges). But if your rollers aren't positioned at the right height, your printing will have a halo effect: dark around the edges and/or chunkier/blotchier than it should be. If you ever notice ink on the back of your polymer plate or on your base -- it's a roller gauge emergency! Adjust your rollers now! Here’s how.

Step 1. While your press is inked up, remove the chase (on platen presses) or the base (on a Vandercook).

Step 2. We recommend checking the roller height in the four corners of the press bed. We’ll start in the upper right hand corner. Engage the form rollers and position them over the upper right corner of the bed.

Step 3. You will be pulling a stripe of ink on the round surface of the roller gauge. Pull the gauge underneath the form rollers so that a stripe of ink is transferred to the rounded surface of the gauge’s cylinder. Measure the stripe of the ink: you want your ink stripe to measure 3/32”. If the strip of ink is less than 1/16”, you’ll have difficulty consistently inking your plate (some areas will appear too light, and some areas will appear too dark). If your strip of ink is wider than 3/32”, your rollers put too much pressure on your plate and cause your printing to be chunky/blurry.

Step 4: On a platen press, to adjust the height of your form rollers: add tape to the rails that the roller trucks ride on. You may have to add several layers of tape. Scotch or masking tape is frequently used for this. If you’re using a press other than a platen press, consult your manual as to how to raise your form rollers.

Step 5: Repeat steps three and four in each corner of your press bed.

Step 6: When your rollers are positioned correctly, you should pull identical 3/32” stripes of ink from the four corners of the press bed, and your printing should be both crisp and beautiful! 

If you continue to notice inconsistencies in your inking after adjusting your roller height correctly, you may need to purchase new rollers and, if using a platen press, roller trucks as well.

When using any kind of polymer printing base with your platen press, it’s vital to keep the gauge pins and the grippers from smashing into—and denting!-- your base. When the press goes to impression, make doubly sure – no, make triply sure – that the gauge pins and grippers will not impact the Boxcar Base’s surface. Here’s how to do this.

You must carefully place your gauge pins on the platen to avoid hitting the base. Place the gauge pins below and beyond where the base will sit in the chase and feed paper to the far bottom corner of the platen. In addition, place the grippers to the left and right of where the base sits in the chase. This will keep the grippers and gauge pins from contacting the base when the press closes for impression. If you need to use the grippers, keep them outside the base but construct a paper (or tape or string) frisket between them to hold the paper.

You might find it easier to position gauge pins if you print on sheets larger than the final trim size, especially if you have a quarter inch margin or less on either of your feed edges. This will move the gauge pins farther from the printing area and from the base – reducing the likely hood of a gauge pin/base collision. Print on the largest possible sheets and trim them down after printing.