View Full Version : Engraving Mirrors

Keith Outten
08-07-2004, 7:42 AM
If you haven't tried engraving mirrors yet you will find it interesting and profitable. I have a local source that I purchase 11" by 14" mirror stock from at less than $4.00 each so it makes for a very inexpensive and elegant material that is suitable for wedding announcements, birth certificates, business logos and even simple designs that can be personalized.

Always engrave mirrors from the back side. Engraving the front side can destroy the lens or your machine so keep this in mind for any projects that have a reflective surface.

When engraving mirrors you are simply removing the silver from the back and leaving a translucent surface that can be painted or use my favorite trick by using colored matte board. Your customer will be able to change the background color to mach their decor any time they please by changing the matte board.

I have a local source to purchase acrylic mirror which can be not only engraved like glass mirror it can be vector cut to any shape as well. Now consider those beautiful wooden hand held mirrors that so many woodworkers make and think about how easy heart shapes, ovals and other designs would be to engrave and cut. Another idea is to use acrylic mirror to make really slick Christmas ornaments. Mirrors are also a really nice way to dress up the tops, inside lids or even the sides of wooden boxes.

Glen Peters
08-10-2004, 5:09 PM
Hi Keith

I purchased some acrylic mirror thru E-bay several months ago but am not happy with the results I get. My acrylic has an adhesive back.
Could the adhesive cause it not to engrave clean and evenly?


Shaddy Dedmore
08-10-2004, 5:47 PM
Do you mean the mirror gets etched in places, but not in others? Or do you mean the mirroring is all gone where it needs to be, but the acrylic is left with ridges and looks poor.

If the latter, could be because it's extruded acrylic, and that's the problem I had. I spray painted the back and it seemed to hide the ridges a bit. I tried different settings to get the roughness better, but I haven't narrowed anyhting down yet.

Of course, I don't have a lot of experience in this field and I could be way off.

Keith Outten
08-10-2004, 7:18 PM

I expect that your problem is with the adhesive backing. The acrylic mirror I purchase from my local supplier Norva Plastics does not have an adhesive backing, it engraves perfectly and vector cuts leave a nice smooth edge. Norva Plastics has plenty of stock specially made for engravers and I never have to worry about using materials that would cause a problem with my machine. I try to be very careful to stay away from PVC and other materials that are not suitable for laser work.

Glen Peters
08-10-2004, 10:53 PM

I'm sure the acrylic is extruded. The vector cut edges look like cracked ice and engraving is never crisp.


I suspect the adhesive also. Oh well, Ebay, cheap- will have to come up with another use for it.


Lynn Kull
08-18-2004, 11:59 PM
Hi Glenn, your not alone on the cracked edges of acrylic mirrors. I purchased mine from a reputable laser dealer, only tried one or two things and haven't done any since. The photo on the mirror turned out great, but when cutting out a heart shape the edges all cracked like it couldn't take the heat? Lynn

Gary Shoemake
08-19-2004, 8:44 AM
Hi there
Do you have a setting for PPI? I'm told that the setting for plastics and acrylics needs to be 1200 or above. I'm also trying with some acrylic mirrors and have had some success using a higher PPI.


Lynn Kull
08-30-2004, 1:43 PM
I received some info from ULS today and they talked about the acrylic mirrors cracking when cut. The solution and it worked for me was to apply masking to both sides, spray it with water and cut it from the front side. They say the acrylic will absorb the laser, (don't know if this would be true with Glass tho?).

I cut out my heart first, then removed the masking and flipped it over into the template made from the cutout and engraved the pictured. Worked great. Lynn

Michael Wells
08-31-2004, 12:59 AM
Hi Lynn,
I haven't worked with too much of the acrylic mirror, but the same thing does work for glass. I use wet newspaper or paper towels laid over the glass to get a good etching on the face of the glass. When I am etching the silvering off the back of a glass mirror, I don't use any paper or moisture, the silvering and the protective covering lase just fine.
The only problem that I have had is, when airbrushing the etching from behind the mirror, getting vibrant colors that work with backlighting. I recently began using some special glass paint from a local hobby shop that works pretty well. But these still wash out in the lighter colors, like yellow, or light beige. If you aren't trying to backlight the mirror the etching works great.

Joe Pelonio
07-26-2005, 1:48 PM
Rather than using paint, if all one color, get some translucent vinyl from a local sign suppy or sign shop and apply to the back. When hung in front of a sunny
window the results are great, also may be backlit. You can invert the image and engrave out the background so that only the image is mirror, for a really cool effect.

Rodne Gold
07-26-2005, 11:01 PM
There is mostly one main reason Extruded acrylic will stress crack (most of the mirror acrylic is extruded cos cast cannot be made to the same thickness tolerance due to the mnfgring process) and that is the presence of a solvent. The heat of lasers put incredible stresses into acrylic and the most common cause of stress cracking is cleaning it after with meths or the like. Same with spraying it with solvent based paints. Even solvents nearbye or solvent fumes can do this. As To PPI , the more you increase it , the more you have a heat affected zone at the cut , you overlaps the laser pulses more. Too much PPI into acrylic will actually generally give a worse but perhaps more "polished" cut , generally the heat promotes a remelt.
Good air assist is the key to getting good acrylic cuts , the idea is the air assist needs to eject the melt so it doesnt resolidify in the cut but not be so strong as to cool the pex so the edge doesnt get a polish. You need a directable jet and the way to see whether you are right with air pressure is to turn it down to where flaming just starts and then take it up a bit to stop this.