Lazer Engraved Blocks
OK…. I was not going to post this information until I had time to finish my testing, but since the topic came up in another Posting, I felt that the time had come to share what I’ve discovered:
For about a year now, my shop has been experimenting with printing blocks engraved by Lazer directly from digital images onto various types of materials. We’ve tried plexiglass and several other forms of plastic such as resin-grave, metal, and many different types of wood. Most of these materials do not produce clean, fine lined blocks when zapped with a 40-watt beam of red light. They either melt, produce ragged edges, are too soft to hold a good image or take hours and hours to cut.
We had little in the way of useable results…. until we tried the type-high, tight grained cherry wood that we use for hand-engraved illustrations. The results with this material are GREAT. In fact, they are SO good that we have abandoned PP plates entirely, in favor of this new process.
Specifically, we purchase 1” cabinet grade cherry, then let it cure for at least a year. (This curing is CRITICAL) Once it’s cured, we plane it to slightly over type high with a planer, and then use a scraper to take off any ridges or marks left by planing. This is the same material we hand-engrave for other types of work so we have a lot of experience making good engraving surfaces . Then we engrave it using a 40-watt machine driven by digital images created with Corel Draw. We cut our blocks to .040 for type and .020 for halftones.
Below is a pic of one block we cut a few days ago. This particular one was rejected due to a couple of layout errors…. but it shows what is easily achievable. The smallest type show is 4 pt Arial Light, which prints cleanly without difficulty on a Sigwalt #5. We’ve also produced and printed a number 120 line halftones, and dozens of line-cuts. .
We’ve done press runs of well over 5,000 impressions of 4pt type, with little or no visible breakdown of the image quality image. As a process for letterpress, it’s one of the best I’ve encountered…. and I’ve been doing this for a loooong time.
Now…. about costs: Since we do all of the work ourselves, we see a considerable savings over farming out PP plates to outside vendors. The only three expenses we have are the cost of the raw cherry wood, the capital expense of the lazer, and our own labor. We have not yet calculated what we would have to charge IF we were to offer these blocks for sale to other shops….. and we are probably not going to sell them. To be honest, we’re far too busy with everything else we have going on right now.
So…. there you have it: a report on Lazer Engraved Wood Printing Blocks. The process works extremely well.
Winking Cat Press
Mobile Alabama
wood engraved 2.JPG
Hi - Great job - I think you’re really on to something. I predict that in a few years many of us will be using this technique. I think some of the 40W cutters are under $2000, not sure how good they are but cheap enough for someone to experiment. The way good type is going up and up, this might be a reasonable alternative. Besides a block of cherry looks better on a handpress than polymer. Cherry will be the next boxwood.
Charles
Ginkgo Leaf Press
And what will you use when all the cherry is used up?
I’ve thought of using casting metal (ludlow/linotype) but my concern would be that laser vaporizes the material, and thus the lead content. Nothing any of us want to breath. Not sure how aluminum or magnesium would be as far as toxicity.
The other thing is this is only a 40watt laser. Far to slow to cut metal for production. I suspect a high enough wattage laser would produce good results in a timely manner in even a steel plate. As said in the other post however, machines of this strength are really out of reach for the hobbyist.
I know you’ve said you’ve tried a bunch of materials, how did fine grain birch finish plywood fair?
Devil- That is a good point….. I’m glad you brought it up.
None of the Cherry we buy is from old growth or naturally standing forrests. It all comes from trees culled from commercial fruit growers, and thus is constantly being replanted. As long as folks eat Cherry Pies, we’ll have a supply of wood.
The disadvantage is that the wood is smaller than old-growth… and so our blocks are limited to ~6” wide. It’s also more expensive, but it’s a small price to pay for peace-of-mind.
We have also done a lot of blocks on recycled wood such as piano-maker’s and cabinet maker’s off-cuts, and discarded furniture. Just because a process is wood-based does not mean it’s eco-unfriendly. We at WCP are VERY eco-minded…. with a complete solar/ wind energy system, and paper re-cycling operation…. so we do understand your concern.
Lammy- Linotype metal or any lead-based material would indeed outgas hazardous fumes, so I would not recommend it. We did try several metals that did not work well, partially for the reason you cited:
Aluminum sheet- produced ragged edges, and the thin pieces tended to melt away.
1/8 Magnesium etching plate- cut very nicely, right up until it caught on fire and damaged my machine. It is very difficult to put out a magnesuim fire, as I discovered.
3/16 Highly polished Mild steel- cuts very cleanly, and makes a beautiful plate… but VERY slowly. It took many passes, and all day to make one 4x6 plate. If I were going to do a project of extremely high value, or an itaglio plate, this is what I’d use….. but for most jobs it would be too expensive on a 40 watt machine.
Brass- shows the best promise. We cut a number of 1/8” medium-hard brass plates, which carried excellent detail when cut to .030” deep. With a 40 watt machine, it is still too slow for production use. The brass also had a tendency to loose detail after a few hundred impressions. It you look at the plates under a loupe you see that the edges are rounding off, much like worn-out type. A harder brass might correct this, but we have not tried it yet.
As far as other woods we tried, we tried everything we could lay our hands on. Cherry was the best. The next best was hard-maple. We bought printing blocks from a specialty company, and cut them. They are almost as good as the cherry. Poplar also works fairly well, but is too soft to hold small details.
The plywoods we tried were Finnish Birch, Luan, HDO, and Japanese Shina (used in printmaking). These are all useable for large images, but do show some grain no matter how fine you sand them. They don’t work well for tiny details because the small details tend to break out along the grain. For 12 pt and larger type, it does produce a useable image. We did not do a long run test with any of these, and I’d guess that they be rather fagile.
Winking Cat Press
Mobile Alabama
excuse my never ending dumb questions… . how about cured photopolymer? Expose the entire block to harden it then cut it with the laser?
I was wondering if the magnesium would catch fire. I think that’s the stuff that’s claimed to be able to burn through the deck of an aircraft carrier.
Your using a red light laser, did you look into CO2 Lasers?
I’ve never tried it, but it doesn’t seem to be the best use of the material. If one is going to buy PP material and use it with a lazer, then it would probably be best to expose it using a quick lazer pass and then wash it out….. this is what the other posting was about, I thought.
About Magnesium: it burns fiercely when ignited with a lazer. Fortunately this particular bit of metal was attached to a larger wood block, so I had something to grab and toss out of the machine. Otherwise it would have ruined it for sure.
Do you do anything to seal the grain after cutting? I’m also curious if a pentrating epoxy like RestoreIt CureRot would extend the length of run.
I have not sealed the grain with anything after cutting, but I did try a block of cherry that had been thoroughly pre-sealed with linseed oil. During the cutting, it smoked a lot more and the end result was not as clean looking.
May I ask what laser machine are you using? I contacted my local laser shop last friday to run a test for me. (I have since bought some maple for the test, but not run the file yet) Funny to stumble across this thread today. How deep are you cutting?
Oops, saw the depth after I posted.
I’m using an Epilog Zing 24, 40 watts that I bought used. The only modification that I made to it was a forced-air ventillation system to keep it from smoking up my office.
WCP: it appears that you are using the face of the wood. I would imagine that the small unsupported portions (like in the seal) might be susceptible to breaking off. Have you considered using the end-grain? perhaps that would be stronger in that fashion.
Equitas-
Yes, I am cutting the face of the plank and not the end-grain. Theoretically, end grain would be far superior in terms of longevity….. and that is what I’d prefer to use, but the time to correctly produce end-grain blocks makes them more expensive. Also, there are very few folks who can make end-grain blocks that do not check or seperate along the glue lines.
The use of side-grain Cherry is a work-around for the cost and lack of end-grain wood. It works well, even for small areas of detail. One thing that my laser allows is sloping of the cut edges, so that fine detail is not as fragile as it appears.
Winking Cat, I have used artboards(tm)
for laser engraving. their endgrain maple worked super. I had a client about 4 years ago approach me about
printing some Willard Clark wood engravings they were to warped to print from the original blocks,fortunatly
Willard had pull some good repros so I had those scaned sent those off to a friend that does custom wood inlays for yachts and pleasure craft and he did the laser work. I had very good results and the client was happy.best james
James- thanks for the tip. I’ll give their end-grain blocks a try.
Winking Cat Press,
Thank you so much for sharing this information. We tried many things when we started out, but never had success and so we abandoned it. After reading your posts, I am definitely going to run out and get some cherry to try.
Question: What happens if you do not age the cherry for a year? I am guessing it warps? Also, would you share where you are able to buy cherry that is from orchards?
Glenwood Morris
Oslo Press Inc.
if the cherry is not aged/ cured for a long time, you run the risk of having it warp along the grain. I’m lucky in that my shop has been curing and planing cherry for a number of years for woodblock usage, and so we have a great deal of experience in choosing good pieces.
My source for wood is from a specialty shop who buys whole trees and cuts them for furniture grade lumber. We’ve had a business relationship for a number of years. As far as I know, he does not sell his wood commercially. I’ll ask though, just in case. I don’t know where other cherry-wood suppliers get their wood, but I would guess that some vendors are better than others.
Wow gents, this is great stuff. The other day I commented that someone should come up with a laser thing that cuts a plate and bye bye film. Actually I must say I still do negs using the good and old positive to negative exposure and maybe I will buy a camera and try with it.
I am very surprised by looking at the picture. You are onto something great. Cherry wood seems fancy but hey, the best result is what you want.
I would be interested on having a plate done, with an engraving I have, it is “Gutenberg First Proof” at his press and looks very clean, from Harpers Magazine around 1890s. It has 0.125 hairlines and I would like to know if you like to try work on a plate for me, if that is OK with you.
Have you found the way back to wood carvings?
Cheers!
Andre
I have one of the cheaper co2 lasers 40w power hx3040 , ive been using it for a year or so for making the plates for hot foil printing and flexographic printing,
recently ive used the same photopolymer hotofoil plates on my heidelberg
I use the stndard photopolymer plates, burn away the gaps and then uv cure it to set it, it will engrave the plates once uv cured, i just tend to do it afterwards ,once cured there ready for use with no drying as i dont have to wash them, on the flexographic i use the flexy photopolymer plates and do the same, you can also engrave and cut rubber sheet as well,
the co2 laser does very fine engraving , but wont touch metal at all
Thanks for sharing! Direct-to-plate is here, I guess.
I just had a job interview with a company making gobos for lighting… not printing, but a lot of the same design considerations. They are still too intimidated by the cost of laser machines to move away from photo litho…If I get the job, I will start poking at them to demo an Epilog or somesuch.
You probably already know the source, but I would point you towards McClain’s printmaking supplies (http://www.imcclains.com/catalog/blocks/cherry.html), as they carry cherry blocks. If I remember, they plane them to around 3/4, so you would have to shim to type height. It is all cured already, so might be a good, if expensive source, in a pinch.