General Printing with the Boxcar Base
Since polymer plates mounted on a base are type-high, there is nothing keeping you from printing type at the same time! Many printers will print a form that includes a smaller Boxcar Base with a polymer image design with metal or wood type combined around one or more sides of the base. This is a great use of both when you want to add an image.
Yes, you can certainly lock up two Boxcar Bases into one chase and print, and in most situations print a letterpress plate that spans the two bases. We inspect our Boxcar Bases and verify they are within plus/minus 0.001” in thickness, parallel and flatness. Still, we’d like your bases to be even closer in height than +/- 0.001″ if possible. Here’s how to do this depending on your situation.
- You purchase one base and have it cut into two pieces: use each piece individually or lock them both back up together for a larger base surface. Your two cut sides should match up perfectly. Slide them together and using quoins, furniture and leading, fill the chase on all sides around the two bases to support the pieces and have a good strong lock-up.
- You already have two different bases in your shop: These should be fine to print. There may be slight variation within the +/- 0.001″ tolerance, so find the two sides most similar in thickness and slide them together.
- You have a base. You want to purchase another base to print with at the same time: We keep detailed specs on each base we sell. When you order your second base, let us know your original base’s serial number—we’ll make sure the bases we ship to you are identical heights so you can butt them together and have a very even printing surface. Where do you find your serial number – on the bottom edge under the Boxcar text.
- You are going to purchase two bases to print with at the same time: Just let us know that you’re planning to print with them at the same time, and we’ll choose the two closest in height from our inventory.
I own both a Vandercook and a platen press – do you suggest that I buy two separate bases, the Deep Relief Base for the platen press, and the Standard Grid base for the Vandercook?
We suggest purchasing one type of base for both presses, so that your presses will be able to share the same plate. It really comes down to your experience: if you’re a new printer, go with the Deep Relief base. Setting roller height can be a longer adjustment process on platen presses and this base will be more forgiving as you work through this. If you can use a roller gauge in your sleep, and you have experience expertly adjusting your inking rollers on your C&P, go with the Standard Base. The Standard Base’s plates give a crisper impression; offers more detail; and are less expensive per square inch.
We totally understand that you want to get the most use and space out of your press. However, knowing about some of the challenges you will face can help you make decisions about the correct size.
First, keep in mind that every press, like every person, has a limit to its strength. A press with a 10 x 15 chase will never be able to hammer a 10 x 15 block of text. You’ll be able to get a good impression using about 60-70% of your chase, depending on your form. Secondly, your base needs to stay put in your chase with a good lockup. To secure your base in your chase, you need to make room for the quoins plus furniture for distributing the weight of the base, and gauge pins. Gauge pins fit in the space outside the base and over the furniture.
We recommend checking out our Base Selection Chart which recommends the ideal size base for your chase. With a 10×15 chase, we would recommend a 9×12 base, for instance.
If you really want to max out the base size, keep in mind your base should be at least 1 inch, preferably 1.5 inches, smaller than your chase. If you use a lot of paper that is precut, it is most likely smaller than your base. This can make it challenging to place your gauge pins and still hold the paper and not hit the base. One safety note, the larger the base in your platen press, the further you have to reach into the press to place your paper. This is very important with a larger press with a motor, so take into consideration your comfortable reach, the speed of the press, and your fingers when locking up a larger base.
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.
Here are our general guidelines for choosing between a deep relief or standard Boxcar Base:
For presses with cylinder inking systems, such as a Vandercook or a Heidelberg Windmill, where press adjustments for rollers are fairly easy to make, we suggest a Standard Boxcar Base (.875” thick).
For platen presses with rollers that run on rails and an ink disk system, such as Chandler and Prices, Goldings, Kluges, etc., where press adjustments for correct roller height takes longer, may have more steps, and can be a little trickier, we often suggest a deep relief base. Why? Many of the platen presses have rollers that are set too low and need quite a bit of taping on the rails to bring them up to type high. So if roller height is not correctly set, the rollers can hit the base or ink the standard base. The deep relief base is a thinner base (.853” thick) and while adjusting rollers and preparing makeready, the rollers usually won’t ink or hit this base.
Of course, there are exceptions to every guideline. If you are an experienced printer with skills in roller height adjustment, a standard base will be just fine for you. If you are already printing on a press with a standard boxcar base and are outfitting a new press, it is certainly easier to use (and remember) the same base and plates for all jobs. Roller height adjustment is the key to good printing regardless of press so this is valuable to learn regardless of your choice of Boxcar Base.
The Boxcar Base is guaranteed to hold plates in register, provided they are standard thickness plastic-backed plates mounted with our film adhesive. But plates that are smaller than .25 square inches may drift under certain conditions due to their small area of contact with the base. Make sure your plates are larger than .5″ by .5″, even if your image is very small.
What happens if you use a Deep Relief Boxcar Base on a Vandercook, Heidelberg Cylinder, or Heidelberg Windmill–some info you need to know?
The Deep Relief Boxcar Base does work fine on cylinder presses or the Windmill — since its base + plates + adhesive still equals a type high surface (.918”). But we feel you can hold better detail on the thinner plates that go with our Standard Base. Because you can get superior detail from the Standard Base’s plates (KF95 or 94FL), if you can get good printing on the standard base, you should use it. That said, some printers who use the Deep Relief base on their platen presses already may want to use the Deep Relief base on, say, their Vandercook too, so that both presses can share plates — this is totally okay too.
If you have a Boxcar Base – we can tell you the thickness of your base down to the ten thousandths of an inch. Just provide the 5-digit serial number on the bottom of your base below the base description and we’ll send you the dimensions.
If you want to measure your own base – we suggest a micrometer that measures to thousandths of an inch. Follow the directions that come with your micrometer, however, basically you will clamp your micrometer’s measuring rods around your base and tighten until it holds the base firmly and securely. Tightening too hard can cause an error in your reading. Read the measurement per the instructions for that micrometer.
Boxcar Bases are measured to the following heights:
Standard bases – .875” plus or minus .001
Deep relief bases – .853” plus or minus .001
If your base is .X” high, subtract that amount from type high .918 and you’ll get the height you want for your plates.
Your maximum plate size is actually the size of your base — your photopolymer plates can go right up to the edge of your base. Obviously your relief images and text should not hang over your edge. This is true for both magnetic bases and the Boxcar Base. If you need a little more base for occasional projects, consider a Boxcar Base scrap to add that extra ½” – 1”. Read more about maximum base size.
For cylinder presses without chases, such as Vandercooks:
bed width: the distance between the rails.
bed length: find the “dead lines” inscribed in your bed. There are two lines, one at the head of the press, one at the foot of the press. Measure the distance between those lines – that’s the length of your press bed.
You need to make sure that your base stays within those lines. If you put your base on the outside of either line, your cylinder grippers can smash it.
For presses with chases
A chase is an iron frame. To get the width and length of your chase, simply measure the INSIDE of the frame. The measurements may be rounded up to identify your chase size, for example, 4.95” x 7.875” will be called a 5×8 chase.
First, figure out why your chase isn’t lying level.
- Possibility 1. Your chase might have cracked some time in the past then was welded to repair it. If this is the case, you may need to file or shave off any excess metal that might interfere with your chase being level.
- Possibility 2. You may have a low spot on your chase. You’ll want to add a shim (a small piece of metal) to the chase to level things off.
In either case, use a professional machinist. They can expertly grind down your chase if needed to create a smooth surface, or they can add a shim to your chase to level things out.
First, let’s talk about what are registration marks. Registration marks print outside the trim area of printing. They can include bulls-eye targets, crop marks, plate information, etc. These marks allow the printer to accurately align separate letterpress plates for multiple color print jobs and better align cuts when trimming.
How do you tell whether you need registration marks for your job? If you are letterpress printing a job that has two or more colors that print up against each other or overprint each other, registration marks help you to set up each plate color for a close printing with minimal to no adjusting.
If you have a letterpress printing design with bleeds, crop marks are useful for a proper paper trim after printing.
If you are printing a design with scores and folding, having those marks designated outside your trim area is helpful for die cutting and finishing work.
If you are sending your letterpress printing project to another location for cutting and finishing, registration marks can be a very smart move for a successfully trimmed job.
If you just want guidelines for trimming, crop marks make a good template.
If you are adding registration marks to your plates, here’s how to use them to register your plate to your base: Plastic backed letterpress plates are see-through and you’ll be able to see and use your Boxcar Base grid lines for registering. Place a registration mark over a grid line at an intersection where two lines cross. This will be your same starting place for the registration marks on a second color plate.