Laser cutting a stencil for wine glass acid etching

[Roger Lueck]

Windows 10
CorelDraw X7, 2017 & 2021
Chinese 100 watt laser

Good Evening Everyone,

I'd like to create a stencil with a laser to be used for wine glass etching. I have attempted to use a laser to etch Riedel wine glasses previously with poor results, mainly due to the amount of lead used in these glasses.

I have had success using "Armour Etch" acid cream to etch Riedel wine glasses and would like to use it to etch some Riedel glasses for a customer.

My intent is to use blue painters tape, transfer tape or other adhesive backed material for the stencil material and cut the stencil with a laser.

The problem with a traditional stencil is that the centers of letters (O, P, D, R, etc.) or objects normally are connected to the stencil body using "bridges". I would like to eliminate the need for "bridges" by attaching the adhesive backed stencil material to a substrate that allows the adhesive to grip substrate, but would release the stencil material when transfer tape is used to remove the stencil from the substrate. The stencil would then be placed on the glass the adhesive backed stencil material bonding to the glass and the transfer tape removed leaving the stencil adhered to the glass ready of acid etching.

The steps of the process would be:
1. Attached the adhesive backed stencil material to a substrate that would not be damaged by low power engraving (steel, aluminum, etc.)
2. Using low power, laser engrave the stencil material to remove those areas to be acid etched
3. Use transfer tape to remove the stencil from the substrate
4. Attached to stencil to the wine glass using the transfer tape to correctly position the stencil
5. Remove the transfer tape from the stencil leaving the stencil adhered to the wine glass
6. The stencil is now ready for the acid etching of the wine glass

This above method is similar to the process used for attaching "cut adhesive backed vinyl" letters and graphics for signs

Has anyone tried the above described method of creating/using a stencil with any success?

Specifically, what materials did you use for the:

Substrate
Adhesive backed stencil material
Transfer tape to remove the stencil from the substrate that allows the stencil to remain attached to the glass for acid etching

An obvious recommendation without knowing much about the project would be to use a vinyl "drag knife" cutter to cut the stencil from adhesive backed vinyl. However, this is not a viable solution as the letters are far too small (11 pt) to be cut with a "contact cutting device" such as a vinyl cutter.

Another recommendation would be to attach the stencil material directly to the glass, engrave the stencil "in place" and then apply the acid cream to etch the glass. This is not possible due to the curvature of this specific wine glass.

Thank You,
Roger

[vince mastrosimone]

Any reason you can’t engrave the glass with the laser?

[Bill George]

Any reason you can’t engrave the glass with the laser?

He said: I'd like to create a stencil with a laser to be used for wine glass etching. I have attempted to use a laser to etch Riedel wine glasses previously with poor results, mainly due to the amount of lead used in these glasses.

[Steve Clarkson]

I stopped using the laser to engrave wine glasses a while ago......I bought a stencil maker and use the armour etch.....one stencil can be re-used 20+ times and they are cheap. You could buy one stencil online for $10-15 or so. There is no issue with the centers of letters falling out and you can get REALLY small text and details with no weeding.

[mike calabrese]

Cutting small text on a good quality vinyl cutter is not really a problem. I have done it many times with some real small details, thin lines and such that everybody said could never be cut on a contact blade machine.
Here is my process for your consideration
my cutter is a Roland 24 inch
change out the knife from the standard 45 degree to a 60 degree blade
Slow the machine down to about 8 or 10 cm / second
play with the pressure setting. With the 60 degree blade you will need to ( should) reduce the pressure.
Test some fine detail cuts before you commit to the actual stencil .
Use good quality vinyl we liked Oracal 651 vinyl for everything. Tried some FDC brand but in my evaluation not up to Oracal quality.
Transfer tape we went with the clear transfer tape can't remember the brand but pretty sure I got it from https://signwarehouse.com.
Don't discount it if you have a cutter you can use.
calabrese55

[Kev Williams]

Suggestion for getting better results with a C02 laser: Change what you're engraving into a halftone bitmap...
If you happen to have Universal's 1-Touch, try it. Just take your black artwork, make it 60% to 80% black, then let 1-Touch create the bitmap.

If you don't have 1-touch, just experiment with 60% to 80% black and just create a bitmap in Corel. I've never engraved glass at more than 400dpi, most often I use 300dpi, both X and Y (although it depends on the machine as to whether the Y axis is even adjustable in raster mode)

I've engraved about 2000 of these wine glasses give or take over the years, using 4 different lasers: (Mods, the owners won't mind me posting pics here!)
BTG wine bar.jpg

This is what the Corel file I use looks like, with part of the 'W' zoomed in...
BTG bitmap.jpg
This was simple black vector art at actual finished size within Corel X4--I painted it 60% black, then hit the 'Bitmaps' tab, /Convert to Bitmap, /300dpi, /black and white, yes Dithered, yes Apply ICC profile (??), and yes Anti-Aliasing... not even sure what they all mean, but it works, so...

My 30w Synrad GCC Explorer, 40w Synrad Gravograph LS900, and 35w Coherent Gravograph LS100, have all engraved these glasses with very good results. Never tried them with my Glass RECI Triumph, but only because no rotary for the thing...

C02 lasers actually break the glass when they engrave, and as the laser beam overlaps on each pass, 'double-breaks' occur (not sure what else to call them), and tiny pieces cleanly break off, leaving glossy 'bare spots' that look like the laser didn't engrave there... Sometimes quite large pieces or slivers leave the glass. The broken-up pattern of a bitmap staggers where the beam hits the glass, which keeps overlapping to a minimum, and seems to inhibit the double-breaks....

[Mike Null]

I suggest you have a look at the Trotec site and see how they recommend engraving glass with the laser. Very good results are possible.