My son, daughter-in-law and I are starting out in letterpressing and have ordered a couple of plates of some of our designs and now that we have them, how do we mount them? On what? They are polymer plates with a sticky back. Is there a home made alternative? Can we make our own? does thick plexiglass work? What are some good sources of these materials? We are really newbies at this and are eager to play with the press we have, but want to go about things the right way. I always say ask questions and you will get the answers!!! We spend a lot of time reading and searching sights and are learning lots that way too.

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Well, here is an answer. Yes, thick Plexiglas would work, as long as it, and the plate, and the adhesive, measure .918 combined. You’d be far, far better off though, and likely happier with your resultant printing, if you invested in a base that was precisely configured for this type of plate, such as those produced by Boxcar Press or Elum Designs. They have web presence.


i don’t use polymer but i mount my mag plates on my furniture, never had a problem, i think gerald is right you will be lots happier with a boxcar base , most people who use poly plates seem to agree. my furnitue method works well, but some furniture might not be the same height. i have also used spacing material, but sometimes it makes for a heavy chase. good luck dick g.

Thanks for the advice. We will check these two out. Mostly the kids are anxious to use their new plates and try some stuff out. Good news for them , they found a business near by that might need an apprentice or intern…. that would be a great learning environment..
thanks dick and gerald

where are you located, i’m sure you could find someone in your area if this doesn’t work out. what kind of press are you using, make sure the shop your going to is letterpress. if you are new to this you should take a few lessons. good luck dick g.

Thanks dick,
We have a kelsey 3 X 5. And we jury rigged a plate to try for one time. Totally can see why you need a good plate. After doing some more reading on the subject it occurred to me that a machinist might be able to help. And we have a steel foundry in our town… And the shop I mentioned ? Well wow, we were walking past the store front when we discovered it and there was a kelsey sitting in the window. Imagine the thrill that ran up and down our spines… hahaha. I think lessons are a great idea. And we live in what might be considered iron country, we live very near taconite and iron mines so heck there has to be someone in our area who could help us. or we may fall back on boxcar or elum. Having that sweet little machine and not being able to do something on it is killing us!!
thanks for the encouragement. I feel like there are people out there who are watching over us!=)

for a 3x5 kelsey i would try to mount your plates on spacing material, leads and slugs, for a small press like yours i think a base would not leave much room for gauge pins. you could use furniture , how thick is your plate, i mount my 1/4” mag dies on furniture, then 2 pieces of chipboard under the furniture brings it up to type high. this should work for the deep poly plates. sounds like pennsylvania is where you might be, excelsior press in new jersey gives lessons, he has a museum with many presses and the old guy alan has many years of experience. i still have the 3x5 kelsey my grandfather bought me for my 13th birthday, i’ve been printing letterpress since 1961. just because you saw a kelsey in a window doesn’t mean they are a letterpress shop, i know of a lot of shops that have these on display in a window, my friend has a pearl in his front lawn next to his mailbox, quite a lawn ornament. good luck dick g.

Sorry I was vague about our location… hahaha. Minnesota.
But as for the printing shop … they do print with letter press. Later my son and daughter in law went in and the old guy gave them a tour and some advice…. Of course he has some newer equipment too, but nothing too up to date and nothing computerized. Cute little fella. You are probably right about our press being so small that we could probably use furniture to mount our plates. We haven’t done too much experimenting yet. Hate for anything to break or get wrinkled etc. if you know what i mean. I know the 3 X 5 is pretty small and is limited, but as we are just learning we thought it would be a good starter press. And we got it for a pretty good price. We are already drooling over bigger presses… ha!

letterpress is worse than alcohol, my wife wants me to go to rehab for letterpress people but can’t find one. she keeps saying bring home one more thing and i’ll get rid of you, but with a 4 car garage bursting at the seams and more stuff coming i’m still here. just remember when printing the more area you try to print the more pressure you need, rule of thumb is only print about half the area of the chase and you should be ok, but everybody pushes the limits. good luck dick g.

so another thought crosses my mind… One of the tips mentions not to use too large of a plate. So am i understanding this that the base that you use to mount your polymer plates to shouldn’t be more than 1/2 of the entire area of the chase. So say my polymer plate is 1 1/2 by 3, so i should mount it on something that size and then pack furniture around it right.. What i think i am understanding is that a plate or base that completely fills the chase in one piece would put too much pressure on it.
does that sound right?

The siz eof the base doesn’t matter, it is the area of the image which you are trying to print. For instance, on a 3x5, you could easily print a line on the top and bottom of a note pad sheet, but if you tried to print a 2”x3” solid block of color, you might well have difficulty getting an even impression and even inking.

Whatever you use to hold the paper in place needs to clear the base as well, so that eats into the available printing area on such a small press unless you use folded paper “gage pins”.

Okay, so my 2 x 3 or so business card plate with print on it should be okay… and i should mount it on that size block and pack around it with furniture… My son thinks that a block that fits the chase would be better cos’ there would be less packing, but i only see that as a time saver, not necessarily a better for the press and the print. am i heading in the right direction?

Another alternative when mounting polymers with double-sided adhesive, is to acquire some intertype blank slugs. 12pt x 30ems is the usual jobbing size and should be obtainable from anyone who has an intertype which is still in operation.
Make up an area big enough to accommodate the polymer and make sure it’s planed down properly when locked up. When mounted the slugs plus polymer will make .918”. The logic behind this is that when you’ve finished the run, and want to dismount the plate, the forme can be unlocked and the slugs peeled off the back of the plate, one at a time, without damaging it. The release material can then be replaced back over the adhesive tape and the plate can be stored and labelled in an envelope. The blank slugs can then, be either tied up and placed on a galley, or locked in a slip chase awaiting further use. I find the best polymers are steel-backs, that can be mounted on a magnetic base. The magnetic bases can be made up, by using either standard wooden block mount or low cornerstone alloy mounts, and then faced with a magnetic membrane.
This membrane has an adhesive backing and is usually obtainable from the flexi polymer makers. They use it on the washout units of their plate makers. These block mounts can be used repeatedly for any polymer with a steel back. The plate can be placed in any position on the mount and will stay in place during the run due to magnetic force.
However, they are easily removed from the mount, by slipping a thin-blade under one corner and lifting them free without damage.
I don’t know the situation as regards polymer makers world wide, but Last Brothers are still producing steel backs in the UK and I believe they plan to for the foreseeable future. Information regarding these can be obtained from:

[email protected]

I normally send s/s copy as a pdf and receive the plate within a couple of working days.
I have also found that the best impression packing for polymers, is:-
Top-sheet manilla over two sheets of bank plus two or three sheets of art next to the platen. The whole lot shouldn’t be any thicker than 3pt.
If a sheet of the job is placed behind the forme and a pull is taken onto the packing, it should come up nice and even. When the sheet of the job is removed from behind the forme, the result should be a crisp and trouble-free run.

Blank Intertype and Linotype slugs are .875” high, which is useable with plates of 95 to 100 metric thickness designation. The same height of base material is available in Elrod cast .875” Low-base (or “Monotabular base”).
For plates of 145 to 152 thickness, Elrod .854 High-base would be used.
For either there may be slight sanding or underlay needed to get to exactly .918”. Linecast slugs vary more than Elrod material.
Note: I should have said that Lino slug shoulders are .875” on US machines. UK mats have a different depth of drive and so a different shoulder height not matched by US Elrod molds.

Letterpress Lady -

I use old photoengraving bases for metal and photo-polymer plates. I also make them to fit the chase holder, eliminating the need for a chase at all when my base is used.

The wood used to mount photo-engravings is the correct height and is certainly sturdy enough. Any variation can be dealt with by packing behind the base.

When the old plate is removed cleanly, the wooden base is ideal for mounting other plates. I have many boxes of useless old commerical engravings, so I have plenty of “raw material” to do this.

I recently made such a base for a 6x9 Victor also make them to fit the 3x5, 5x8 & 6x10 Kelseys.

To solve the gauge pins issue, one option is to use the super low Megill Flexible Gauge Pin. Another is to cut slits in the tympan. See for an illustration of this technique.

- Alan

Hi Alan,
Where can you get the Megill flexible gauge pins and what do they look like?

Painter - & all -

The Megill Flexible Gauge Pins look like a “T” made of spring steel. The ‘wings” flex up to guide the sheet, then can be pushed down - without being crushed - by the gripper or even the plate base.

Yes, I do have a good stock of the original Megill Flexible gauge pins. They were originally designed to be used as as a side guide that would fit under the grippers without being crushed, but are just the thing to use with the Boxcar Base or our Excelsior Chase-Base. They cannot be crushed.

I have more information - and images - of these and other gauge pins on our Megill Gauge Pins page at

I don’t want to be flagged for trying to make sales here, but for more on our Excelsior Chase Base - visit the web site.

We mill our bases precisely to fit your press just like your chase does - no need for chase, furniture, quoins or a reduced image area. We have over a dozen presses in our collection and can make a chase-base to fit any of them.

And, when you add in a set of Megill Extension Feed Guides or home-build your own platen extender, you can get a larger sheet into the press as well and really get the image area you were hoping for when you got your press.

- Alan

I’ve used the flexible gauge pins when necessary, but I can’t think of a worse gauge for everyday use. The only positive attachment is two very shallow prongs that you tap into the tympan once you are in final position. And if you are feeding heavy stock, or have a heavy hand, you may easily dislodge this tenuous connection, leading to misregister. Otherwise it would take sealing wax or tape or the like to secure them in place.
Megill’s other low-profile product, the Fleur-de-Lis gauge is about 6 points high, but that’s too much for an all-over base even with .060” plates.
Cardboard guides could be the most useful here.