What’s the smallest size plate that I can print on my 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.
How are plastic-backed and steel-backed plates different?
When mounted on their appropriate bases, plastic-backed and steel-backed photopolymer plates both create type-high surfaces for letterpress printing. Both plate types are recyclable. We’ll talk about some of their differences below.
Plastic-backed polymer plates are flexible, transparent, easy to cut, and mount onto a Boxcar Base for simple registration. You’ll find these plates:
- can be cut with scissors in both their unexposed and exposed forms.
- are transparent, meaning you can see the Boxcar Base’s grid through your plate. This allows for simple alignment of your plates to your base: For perfect registration, align a certain element of your plate to the grid: take a horizontal or vertical element in your plate (this could be your registration marks, or a horizontal line in your artwork) and line it up to the grid.
- eliminate plate creep (steel-backed plate users sometimes experience this while on press). The plastic-backed plate’s adhesive is shift resistant, giving you a secure, strong hold during printing (but the adhesive also peels up easily when you’re done printing)
- allow printers to print two color jobs using one plate if the design elements don’t touch. Cut out the second color images/text with a craft knife or scissors and set aside. Print color #1. Set your second color images back in place and pull up the first plate for color #1—perfect registration!
- allow designs to be ganged up on plates closely to save space (and money).
- are reusable. You will be able to reuse the plate many times if you keep the adhesive protected with the blue overlay after printing. You can also replace adhesive for even more extended plate use.
- more prone to curling, especially with large solid areas over time.
- If purchasing unexposed plastic-backed polymer plates, you’ll also want to purchase film adhesive to adhere your plates to your base. If we’re making your plates for you, we include adhesive.
- are suitable for metal clay jewelry.
- Over here at Boxcar, we use plastic-backed plates for all our printing (the Jet 94 Clear plate paired with the Standard Boxcar Base).
Steel-backed polymer plates are compatible with magnetic bases, generally the Patmag or Bunting base. Steel-backed polymer plates:
- require cutting with a metal shear or heavy-duty trimmer. You can use tin snips, though you may end up with kinks in your plate, as tin snips won’t cut as cleanly.
- sometimes shift and creep on your base during printing. Magnets in the base effectively hold a plate from peeling but cannot always hold a plate from moving side to side. The cylinder or rollers of a press can move steel-backed plates out of register (that’s “plate creep”).
- are not transparent. Because magnetic bases aren’t gridded (and you can’t see through these plates), you’ll have to align your plates to your base with a line gauge and possibly registration marks. This works, but it is more time consuming and there’s more room for error.
- are rigid, meaning they don’t bend well. This inflexibility can cause plates to kink and warp when handled so that their corners may work up while on press. Steel-backed plates are, however, very durable and not prone to curling over time.
- can be more expensive than plastic-backed plates because you may require registration or crop marks which makes for a larger plate.
- are difficult to get on and off the base, especially when the base has inlaid magnets. When placing metal plates on a magnetic base, keep fingers clear so they don’t get pinched when the magnet grabs. When taking your plate off the base, try an ink knife to pry under the plates to release from the magnetic base.
- have sharp edges, which dictate extra care when handling.
- can be used for a wide range of printing and impression—on leather, metal clay jewelry, ultra heavy-weight paper stocks. Steel-backed plates can also be used on etching presses when relief printing is desired. They are not suitable for high temperatures of foil stamping though.
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”) and that is the critical issue for all bases and plates. There is the advantage of holding a slightly finer line with a standard plate but let’s be realistic when we compare. The 94/95 plates will hold a 0.25pt line and the 152 plates will hold a 0.35pt line (when talking inches that is a .0035″ line compared to a .0048″ line. Not much to quibble about. We just like the way a 94 plate works on our windmills with our standard base and that is how we started years ago in the infancy of Boxcar Press. 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.
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 are less expensive per square inch as they are slightly thinner but all plates, when paired with the correct base, equal type high (.918) and that is the most critical factor.
If I have a 10 x 15 chase on my press, why can’t I use a 10 x 15 base?
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.
What’s the maximum size polymer plate I can print on my base?
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.