If you start to see gunk stuck in the adhesive (cat hair, human hair, your lunch crumbs, etc.), then it’s time to put new adhesive on your polymer plate. This should be a pretty easy process but does require a little muscle.
First, peel up the old adhesive to remove it. You’ll need some good fingernails to get between the adhesive and your plate. Since the adhesive holds onto the plate strongly, you can potentially kink the plastic backing if you’re not careful. We recommend that you lay the plate face down on a flat surface. Hold the plate down with one hand while peeling the adhesive off with the other. Try and keep the plate from flexing inordinately while you carefully tug the adhesive off the back of the plate. The adhesive might tear into pieces, but you can simply pull it up in strips.
Now, put on the new adhesive. If you have purchased a 12” x 18” sheet of adhesive, lay the blue release paper on a flat surface and have the brown silicone paper side face up. You will remove this silicone paper to show the sticky adhesive. If you have a roll of adhesive, pull out or unroll the adhesive so the sticky side is face up. When you first mount the adhesive to the plate, start with one side or corner of the plate and lay down the plate to the adhesive so that it makes as few air gaps or bubbles as possible. If the bubbles happen, work them out with your fingers or pierce them, through the back of the adhesive, with one prick of an Exacto knife or awl. You should be able to get all the bubbles out at this point.
If bubbles form underneath the plate when you mount it to the base, first try working these out to the edges of the plate with your fingers. If that fails, you can puncture the bubbles by sticking an Exacto knife through the BACK of the plastic backing of the plate (the blue side) to release the trapped air.
We recommend that you use a single loop version of a shoelace knot on your apron. This holds the apron shut securely while printing but also allows for easy removal with one hand behind the back.
Kreene, a flexible and matte transparent plastic, is used in a platemaker’s vacuum frame to hold films securely against photopolymer plates during exposure. But over time, it’s the nature of kreene to get wrinkled and lose flexibility. When you find that your kreene no longer creates a smooth seal, it’s time for a kreene replacement! At Boxcar Press, we replace our kreene every few days, but we process a lot of plates. With lower use, kreene can last for several months.
To replace your kreene: cut out a square of kreene to the size of the previous kreene piece (your kreene will be slightly larger than the grooves in the vacuum table). If your platemaker has one, pull the round bar out the previous sheet of kreene. Affix the new sheet of kreene to the bar with double-stick tape. Lay the kreene in position on the vacuum table and turn the vacuum on. Work out any wrinkles in the kreene so it remains flat. Using double-stick tape, affix the kreene edge opposite the bar to the vacuum table. You can then roll the kreene out over your vacuum table and start exposing your polymer plates. To increase the life of your Kreene, roll it out flat in your platemaker at the end of the day.
A platemaker’s brushes wear out after prolonged use: these brushes should be replaced every 6-36 months. You can tell when a brush is tired out because the bristles are matted down. You can lengthen your brush life by keeping the brushes wet all the time and running your fingers through them to encourage the bristles to stand up. We sell replacement brushes for all of our platemakers: please e-mail or call us to order these.
Magnetic mounting rubber and rigid mounting rubber come pre-sealed. Over time, this seal breaks down. You can make touch-up repairs with our green die sealer. Remove any old die sealer and apply green die sealer in a thin bead to the edge of the mounting rubber. Let dry overnight.
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.
Photopolymer supply orders ship from our warehouse within 1-2 business days.
Custom Platemaking orders ship depending on the service you choose:
We offer a 1 business day turnaround, or Same Day Rush – an extra fee service.
For shipping in the USA, we offer UPS Ground, UPS 3 day air Service, UPS 2 day air Service, UPS Overnight morning, UPS afternoon Saver and UPS early Am (before coffee) 8:30 am service.
For International Customers, we offer US Postal Priority or Express Mail and UPS Worldwide Saver.
Remember that the days refer to business days and not weekends.
For platemaking, the day your order is completed (Order Complete) is the day your order ships. You will get a UPS tracking number via the log-in email on your account. Your invoice will be shipped in a separate email. Review your Order History to see all past and current orders for your status. For international orders using the US Postal Service, you will receive an email with your tracking number.
For Supplies – an email will be sent with the tracking number.
For supply orders: Orders typically ship within 1-2 business days. If you need your order immediately, we encourage you to request expedited overnight shipping. However, if you’re in a serious letterpress emergency, please place your order before noon EST and mention that you’d like same day shipping. We’ll do our best to make it happen!
For platemaking: place your same day rushes by 1 p.m. EST.
Supplies: We ship supplies to Canada via UPS Standard or UPS Worldwide Saver and US Postal Service.
We ship international orders (outside of Canada) via UPS Worldwide Saver and US Postal Express Mail.
We think our online ordering system is pretty nifty but of course you can phone in your order to us by calling 315-473-0930. We love to talk to our customers.
Platemaking: We ship platemaking orders to Canada via UPS Standard or UPS Worldwide Saver and US Postal Service. We can ship Worldwide Saver to any international location or opt to use the US Postal Express Mail. These options are all at the click of a button through out platemaking site.
Printing: Yes, we love working with international clients and sending off printed letterpress beauties to destinations far and near.
Supply orders: please call us or e-mail us as soon as possible.
Platemaking: First, log-in to see your order and check its current status. If we haven’t begun processing your order (STATUS – RECEIVED), you’ll be able to change your order details or upload files online. If we’ve already begun working on your order (STATUS – IN PLATEMAKING), please call us or e-mail us immediately, as you won’t be able to adjust your order online and we can see if the production process is already too far along. At this point, we can still change your shipping options and shipping addresses. If your status is BILLING COMPLETE, we will not be able to make any adjustments at this time.
For supplies, please call us as soon as possible to cancel your order. We will have to discuss refunds and crediting accounts as your online Supply Order has already been charged for payment.
For Platemaking – you can call us right away or you may be able to cancel your order online, if your status is still in RECEIVED or ON HOLD.
Log on to platemaking and you’ll see all current orders. Choose Complete Order to cancel your order. Confirm when it asks if you want to proceed. Your order status will reflect Order Cancelled.
The option to cancel is not available once we move your ticket into platemaking production. Cancelling after this step may incur some production costs. Please call us right away to minimize those costs, if possible.
It depends on the plate. If you’re purchasing unexposed plastic-backed plates, you’ll need adhesive to adhere the plate to your printing base. We sell adhesive in 12×18 sheets and 27 yard rolls. Apply to the back of the plate after processing. If you’re purchasing unexposed steel-backed plates, there’s no need to purchase adhesive. Adhesive is included if we process the plastic-backed plates for you.
As long as you’re careful about not getting dust or debris on the adhesive, and you carefully replace the blue protective release paper after use, the adhesive on your letterpress plates should remain sticky for many years. Keep in mind that adhesive can always be inexpensively replaced.
Instructions for using the Stouffer Gauge to accurately figure out the exposure time for your photopolymer plates: The Stouffer gauge is a reusable piece of continuous-tone film that you should use to test photopolymer plate exposures. Place the Stouffer Gauge in contact with a 1” x 6” strip of plate material (after you peel off the plate’s protective plastic cover). Then expose the plate.
You’ll have to guess the first exposure time because that varies depending on the equipment that you use. Start with the exposure time listed on your plate’s tech data sheet. For exposure times, please keep in mind that these times are for commercial photopolymer platemaking equipment. Any alternative photopolymer platemaking devices may have very different times and you’ll have to experiment more to find your ideal time.
Also check the plate’s tech data sheet for the Stouffer value you’re trying to hold during exposure. For example, the 94FL has a Stouffer value of 18. Make sure that the exposure used with the Stouffer Gauge hardens the plate for all the numbers up to and including #18. If you goal is #18, and #19 and #20 start to harden during your exposure time, then your exposure time is too long– decrease the exposure time. If your goal is #18, and #17 hardens but #18 washes out on the test plate, then increase the exposure time.
You most likely will have to expose several different test plates at several different exposure times to find the perfect exposure. Since the Stouffer gauge is small, you won’t waste much plate material in the process.