Laser-Cut Love

I said in my last post that I finally got to do some printing last week, but I didn't go into further detail. The reason being that Glendon and I were combining our resources and experimenting with using our powers for letterpress good, and I wanted to write it up in a separate post.

Glendon's department at school recently purchased a new laser cutter, and he’s one of the people testing it and figuring out not only how it works, but its utilities and limits. I mentioned that I had read a post on Briar Press where a printer discussed using a laser cutter to make type-high woodcuts. Serendipitously, Glendon was way ahead of me, and I was like “score! Wood type just for me!” We’ll see about that, but our first experiment was pretty promising.

Last week he finally got a chance to try it out and he chose one of the free, vectorized cuts from Briar Press and made a woodcut initial. He used 3/4” finished plywood, so that it had a very smooth face. We’re going to try cherry too, a la the Briar Press post, but plywood seems to be working fine. The laser cutter is a 75-watt Epilogue CO2 laser, which is probably overkill for this sort of engraving since Winking Cat Press seems to be doing just fine using a 40-watt.

There are still a few kinks to be worked out, number one being wood height. Like I said, Glendon only had 3/4” wood, so he had to build it up to type height with sheets of acrylic. This process took a while and in the end one corner was still a bit lower than the others. We ended up using a few sheets of regular 20 lb paper cut to size and strategically placed under the cut to even it out. That was pretty easy and not a big deal; however if anyone knows a good source for type-high wood, please share. I found one site, but those prices aren’t cheap. In the meantime, we’re going to try to work out a better system of building up the cuts. Perhaps we’ll try to find two pieces of wood that equal type high when put together. When I say we, I don’t actually mean me. But look! Isn’t that cool?

We had a couple other fixable problems: the wood either got dinged or had a knot in the middle of the A where the blank spot is. I can fix that with makeready, but it would be much easier to just avoid it in the future through better wood examination and care. And then Glendon forgot about the whole reverse printing thing and neglected to reverse the image before printing it with the laser cutter. I’m pretty sure he would have noticed this if we’d been printing pretty much any other letter besides A, but for testing purposes, who really cares?

We didn’t really try to get an impression or anything because we were printing on a hard coated paper, and just getting the block even was rather time consuming. Actually, I signed up for this letterpress swap thing but naturally left it till the last minute, so this new process is already proving pretty handy. I might try to get some impression with one of those cuts since I’m using 100% cotton paper, and we’ll see how it goes.

Anyway we had a really good time printing the cut and doing makeready and stuff. Glendon’s often around while I’m printing, but it was so great actually doing the whole thing together. For me, it was basically the best date ever. Glendon had fun too, but I don’t think letterpress printing is his new passion or anything. Hey, as long as he keeps on playing with printing cuts on the laser cutter, it still seems like a pretty good partnership.

Comments

[Rich]

Very nice. We have a CNC rounter at work that I'm attempting to use to make some wood type. If you're going to stick with plywood, get some 5/8" thick Baltic Birch plywood. This is aircraft grade. It has more plys all of the same grade wood with no voids. You can glue two pieces together in a larger sheet (a vacuum press works well here)and then run it through a wide belt sander to bring it to type high. These will have either a digital or other readout that is easily adjustable in decimal increments. If you want to apply a hard finish afterwards you could always do that seperately.

If you wanted to try a hardwood, you may want to avoid cherry with the laser as it's notorious for burning even with regular woodworking tools. I don't know how it would work with a laser but hard maple might be a better choice and it is also harder and can be finished to a smoother surface. If you do go with hardwodd, do a glue-up of several pieces, alternating the direction of the growth rings as in a table top so it will be more stable. As a fellow cabinetmaker Glendon will know what I mean.

Cutting into endgrain on hard maple is another option and is the way wood type is actually made but also requires glue-ups except for the smallest pieces.

[Maggie]

Thanks Rich! I knew you would have some good advice with this -we'll definitely check out the Baltic Birch plywood.
I think Glendon is planning on testing all sorts of different hard wood, so we shall see how those work with the laser.

[Rich]

I keep coming back to look at the print and block. It's pretty cool and the laser did a great job.

[Winking Cat Press]

A note from Winking Cat Press-

Great work! I'm glad to see that my original post on Briar Press has inspired others to try the technique. My shop has been having great success using lasers, and I am hoping that by learning from each other, we as a community can bring the technique to full development.

We have experimented with plywood quite extensively, and we do not like it. The surface is a bit too soft and grainy, even with high quality material, to support very fine type or details. We've also used a number of different woods including maple, poplar, white pine, and cherry. The cherry works the best, maple second best and poplar third. The fact that cherry chars is actually an advantage... with a laser it produces VERY sharp edges. All of them work, but the harder woods carry the best detail.

About the "type high" problem, it's not a big deal. 3/4" high material can easily be shimmed up using a 1/8" piece of masonite and a sheet of chipboard. We've got a proof press with this shim permanently installed, and we never have to worry about it.

About laser strength- the 40w machine does cut the wood well, but a 75w would be faster.

Keep up the good work!

Dave
a.k.a Winking Cat Press

[Glendon]

Hi Dave and Rich,
Glendon here. Thanks for the feedback and advice. Of course I was a little embarrassed to have knowledgable printers looking at my non-reversed, non-inverted block but we were really excited by how well it worked so Maggie went ahead and posted it.

I have actually become increasingly fond of that plywood. Since Maggie posted I found some shimming material that is just the right thickness (brings it up to .920") I should point out that it is pretty high quality stuff (no voids) with what I am fairly sure is maple veneer on both sides, sanded very smooth with a factory sprayed satin finish (polyester maybe?). This was not by design but because there happened to be 2 full sheets of it lying around and unlike other available stuff it was already flat. Still I think it was fortuitous. I remain anxious for the schools woodshop to reopen so I can plane some cherry and test that out but I was really amazed at the detail and the quality of the impression that the plywood gave.

I am sure there is cherry in my future but this is good enough for me to use while I hone my Adobe Illustrator skills.

Anyway, thanks to you both. Dave, your posts have already helped me out a lot (for instance I can forgo testing any plastics for this purpose). Rich, I had been thinking that a wide-belt sander would do what I need. Unfortunately I have no access to one. Do you?