Laser engraving darkening

[Don Corbeil]

yes just wipe off the stain the engraved area will hold the stain the finished area will wipe off.

Yes, exactly. The sealcoat will allow wiping off the finished area, and helps to minimize bleeding from engraved area into the grain.
I will use both spray (zinnser dewaxed shellac) or brush on liquid.

[Samuel Espy]

...What I'll often do to minimize the bleed is to engrave, sand, sealcoat, then stain the engraved area. ....

Don, what is your reasoning behind sanding after engraving rather prior to it as part of a surface preparation process? Is the purpose to remove engraving smoke/residue or something else? I am certainly not being critical. Your beautiful work speaks for itself. I just suspect there is something that I am missing that might prove useful. I, like everyone else, have spent time trying to develop a repeatable, inexpensive, yet quality process for darkening wood engravings (particularly photo engravings). I have had the best luck with 1) preparing surface (sanding, clearcoat and often wax), 2) apply transfer tape, 3) engrave, 4) spray lacquer (helps avoid bleeding) 5) spray paint with several very light coats of brown flat paint, and 6) remove transfer tape with plastic razor blade. It produces good results when done carefully. However, a very discerning eye still might perceive the paint in the engraving.

You note in a later post that you use "zinnser dewaxed shellac" as your sealcoat. Is this this product. If so I am confused as to why the stain does not darken the non-engraved areas which i think from your description are only coated in this sealcoat. It seems the purpose of this dewaxed shellac is to allow all stains to stain beneath it. Does it not stain the non-engraved areas because you wipe on and off fast or something?

I would much rather use a stain as you describe as it looks more natural, but previous efforts have always had unacceptable bleeding. I am amazed at how little bleed you have in the beautiful engraving of the dog (St. Bernard?). Maybe I will try your stain and sealcoat. Do you not seal the complete surface with clearcoat prior to engraving? I am surprised that the stain does not darken the non-engraved areas in addition to the engraved areas since if you do not clearcoat both areas are only coated with sealcoat.

Thanks in advance.

[Don Corbeil]

Don, what is your reasoning behind sanding after engraving rather prior to it as part of a surface preparation process? Is the purpose to remove engraving smoke/residue or something else? I am certainly not being critical. Your beautiful work speaks for itself. I just suspect there is something that I am missing that might prove useful. I, like everyone else, have spent time trying to develop a repeatable, inexpensive, yet quality process for darkening wood engravings (particularly photo engravings). I have had the best luck with 1) preparing surface (sanding, clearcoat and often wax), 2) apply transfer tape, 3) engrave, 4) spray lacquer (helps avoid bleeding) 5) spray paint with several very light coats of brown flat paint, and 6) remove transfer tape with plastic razor blade. It produces good results when done carefully. However, a very discerning eye still might perceive the paint in the engraving.

You note in a later post that you use "zinnser dewaxed shellac" as your sealcoat. Is this this product. If so I am confused as to why the stain does not darken the non-engraved areas which i think from your description are only coated in this sealcoat. It seems the purpose of this dewaxed shellac is to allow all stains to stain beneath it. Does it not stain the non-engraved areas because you wipe on and off fast or something?

I would much rather use a stain as you describe as it looks more natural, but previous efforts have always had unacceptable bleeding. I am amazed at how little bleed you have in the beautiful engraving of the dog (St. Bernard?). Maybe I will try your stain and sealcoat. Do you not seal the complete surface with clearcoat prior to engraving? I am surprised that the stain does not darken the non-engraved areas in addition to the engraved areas since if you do not clearcoat both areas are only coated with sealcoat.

Thanks in advance.

Samuel, thanks.
Yes, I do sand after engraving to completely remove the residue and prepare the surface for sealing. The sanding also lightens up the portions that are not engraved, increasing the contrast. I may seal with zinnser a couple of times until I get a good coat, and like you, I sometimes use a lacquer for woods that tend to bleed. I then stain (restor-a-finish dark oak) and make sure I wipe off the stain IMMEDIATELY from the un-engraved portions of the piece. If I still get excessive bleeding, or some stain going through the seal, I will light sand again to try to clean and lighten it up. The key for me is that I may go through a few cycles of staining and sanding to get the contrast I want. When I get there I then lacquer finish the entire piece.


I haven't tried the transfer tape method for engraving photographs, does this tape seem to work OK for photoengraving?

[Samuel Espy]

Thanks for the clarifications, Don. In my experience, one of the keys for using transfer tape as a masking technique when engraving photos is to engrave deep enough into the wood such that the transfer tape adhesive is vaporized away. Otherwise, the paint or whatever you plan to use as color fill will obviously not adhere to the engraved areas of the wood.

[Bill Reibelt]

I Varnish all of my timbers before lasering or CNC carving. This allows the area lasered to be paint filled or painted with out bleeding.

[Klaus Madsen]

Lee's right, I also ran into this on a book (Journal) cover that was very light tan thin leather. I burned the lettering into it and the lady wanted it deeper. The next pass was into the hardboard underneath that happened to be black so it worked out nicely.

I do that all the time, and I lower the speed and power. But I have to say that I really would like it darker, nearly black.
I know the numbers are different for all machines but on my 100w Redsail I run engravings at 1oo mm/s and around 16% power.

[Bert Kemp]

What are you engraving "Leather? Try increasing your speed and your pwr and take it out of focus about 1/8 inch.

I do that all the time, and I lower the speed and power. But I have to say that I really would like it darker, nearly black.
I know the numbers are different for all machines but on my 100w Redsail I run engravings at 1oo mm/s and around 16% power.

[Glen Monaghan]

I've done the same defocus trick for cardboard and it does help get a darker result without burning through, but it made for a "softer" image. If someone is expecting crisp lettering or details, taking the beam out of focus may get the engraving darker but is going to disappoint them on the reduced details.