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. 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! We have a great video on setting roller gauge height in our Boxcar Training Videos and step by steps are listed here.
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. Strapping tape or plumber’s silver 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.