It’s important to keep the grid on your Boxcar Base clean so you can see its registration marks when printing. If your rollers ever lay ink down directly on the base’s surface, STOP! STOP! STOOOOOOOOOOOOOP! Don’t keep running the press because something is out of alignment. Then ask yourself:
- Are your rollers at type-high? Using a roller gauge, check to make sure your rollers are set for type-high printing material. The surface of the base is far below type high and should never come into contact with the rollers.
- Is your base flat in the press bed? Take a piece of onionskin paper and try to slide it between the base and the press bed – if the onionskin paper fits, one of the corners of your base is working up in the press. Frequently this is caused by tightening the quoins too much. Since the Boxcar Base won’t work up as easily as handset metal type or monotype, you don’t need to tighten the quoins quite as hard.
Still getting ink on your base? If, after checking the roller height and loosening the quoins, you still have problems with ink on your base – contact us and we’ll assist you in problem-solving further.
Most of my plate is printing fine, but one or two areas of the plate are printing heavy. What do I do?
More often than not, this is a result of roller problems. It could be the height of your rollers or your rollers can have an uneven or flat spot on the surface (read more about roller gauges). If you processed your plates yourself, there’s the chance your plate wasn’t processed correctly and you have “fat” text, which can cause some areas to look heavier.
Rest assured that ink on your base is a cosmetic problem; ink won’t damage the tolerances or the thickness of the plates. But if your base’s grid is covered in a pretty shade of PMS 2756, registration will be difficult, as you won’t be able to see your grid well!
You want to try and remove ink from your base before it’s dried. Aluminum is like your skin, with millions of pores that will absorb the pigments of the ink. But unlike your skin, aluminum’s surface doesn’t shed. If ink dries in these pores, it’s very difficult to get out. When ink contacts the base, clean it off immediately with any press wash so that you’ll continue to have a beautiful gray surface to attach your plates to.
If ink has dried on your base, use a Mr. Clean Magic Eraser sponge (or similar generic product) and Simple Green (found in hardware and drug stores). Wet the sponge and squeeze out excess. Wipe your base to start to remove all the ink. Sometimes the sponge will do it all. If you have some ink remaining, use a little Simple Green and wipe again. This will do the job beautifully. Rinse out the sponge until clean and let it dry for the next time. Dry the base with a soft rag.
Most printers who use the Boxcar Base have very clean bases because they make sure, like all their other non-printing surfaces, to keep things clean and tidy during the whole course of the printing process.
Like our skin, plates can be affected by the room temperature, humidity, and age. When humidity levels are low, the plates can look and feel brittle. With the passage of time, the thinner polymer on the plate edges are pulled towards the denser polymer text and images on the front—this causes curling. With a life expectancy of up to 1 year or more, polymer plates do age, but these simple steps can hydrate your plates and give them extra longevity.
Step 1. Place your plate back in your platemaking washout system for up to ½ a minute (or, if you don’t have a washout unit, simply immerse in water). We suggest room temperature for a quick dunking. A ½ minute may only be necessary if your plates are severely curled.
Step 2. Sponge off the water and place back in the drying oven of the platemaker for 5-10 minutes. If you don’t have a platemaker, use a hair dryer to warm the plate and make it more pliable. Placing your plate in a box and blowing the hair dryer into the box will keep the warm air more contained and warm the plates more effectively.
Step 3. After the plate warms and starts to become more pliable, place the plate in its bag and set a heavy object on it to keep the flattened shape.
This should help your plates relax so you can adhere them to your base for additional print runs.
Here’s some final advice:
- if using a hair dryer, take care to avoid putting it too close to the plates.
- be patient, as warming the plates takes time.
- watch that you don’t handle your letterpress plates too roughly after the wash and during drying so your relief images don’t chip.
- remember to store your plates flat out of direct light and in a bag so that fluctuations in humidity don’t affect the polymer.
- check your adhesive backing, to see if the adhesive needs to be re-applied to the back of your polymer plate for a secure hold on your base.