Glass Engraving

[Peter Meacham]

What is the purpose of putting wet paper (newspaper, paper towel, etc) on glass - such as a wine glass - when you engrave it?

Does it improve appearance of the engraving? If so, what is the difference between engraving it "bare" vs. "wet" please.

Thanks, Pete

[Stephen Beckham]

Pete,

IMHO, it makes a huge difference in the cracks that the laser will make in the glass surface. The wet towel keeps the heat concentrated on the spot versus letting it spider out like a rock in a windshield. Obviously a lot smaller basis...

When I'm doing plain text like block lettering, I won't worry about using the paper towel in most cases.

When I have intricate font or a graphic, I absolutely use it. If you try to put two dots (or more) really close without the paper, you'll have chip out's that will ruin the design.

When I do anything that may be introduced to heat/cold over and over, I absolutely use it (wine glasses etc). I'm not sure, but I'd hate for an uncontrolled split to run out in the hot cycle of the dishwasher...

Again - all my opinion and you'll get several more. BTW - my favorite paper towel to use is the plain brown paper towel commonly used in restroom towel systems. Seems to hold water longer and easier to wet than paper towel. DON'T use some paper source with quilted or other patterns - it will transfer onto the glass.

[Mike Ireland]

You might also try using a 70% grey instead of pure black. It tends to spread the laser pulses out a bit and reduces the chipping and scaling that you sometimes see on glass.

[Garrett Nors]

You might also try using a 70% grey instead of pure black. It tends to spread the laser pulses out a bit and reduces the chipping and scaling that you sometimes see on glass.

I hear this depends on the laser...I have an Epilog and the % gray technique (I tried 50, 60, 70, and 80%) didn't work well for me at all. Left the edges very fuzzy.

[Brian Robison]

I use dishwashing soap applied to the glass and the blue shop towels wet. The shop towel brand allows you to conform to the shape of the glass.

[Peter Meacham]

What about PPI or Frequency (depending on laser) - what do you guys run - or does that not come into play when doing raster engraving?

Would a lower PPI reduce chipping and chance of the item cracking while engraving?

[Brian Robison]

People will disagree but I use 600dpi.
I've tried everything for fine detail that was suggested.
My best results were using soap and shop towels and 600dpi. Bump up the power (or slow the speed) to compensate for the radius of the glass and set the focus between the high spot and the low spot of the graphic.

[Michael Hunter]

I like the quality of 600 dpi on glass, but only use that if it is a known glass or I have some spare bits to experiment on.

I find that the variability between different glasses and different colours of the same type of glass is largely overcome by engraving at 300 dpi.

In a nutshell, 300dpi = coarser result but more consistent.

[John W. Love]

Why? Because Frank said so. Nuff said! lol
If Frank said rub fresh buffalo dung on it before lasering, a lot of folks would wonder about it, but there would still be a rush on buffalo dung the next day. :D

[Steve Clarkson]

He told you that trick too? I thought that it was a little messy getting it into the laser, but it seemed to work for me too!!!!

[nancy barry]

The best way to "see" the difference is to test this on some scrap window glass.. I did this with the word "TEST" in bold font at several different sizes. I rastered plain, with wet paper, with DW layer, with wetpaper over the DW layer. I think the result will tell you what works best on your laser.

hth, nancyB

[John Barton]

Over here I see people using wet newspaper a lot on glass and plexi.

[Bill Cunningham]

Why? Because Frank said so. Nuff said! lol
If Frank said rub fresh buffalo dung on it before lasering, a lot of folks would wonder about it, but there would still be a rush on buffalo dung the next day. :D

I tried buffalo dung, the results turned out pretty crappy...:D

[Dan Hintz]

I tried buffalo dung, the results turned out pretty crappy...:D
Keep your opinions to yourself... no need to cause a stink.

[Bill Cunningham]

Keep your opinions to yourself... no need to cause a stink.

Ooops sorry, I didn't mean to 'step' in it..Been There Dung That:rolleyes:

[Jim Watkins]

I keep an old phone book in my shop and use the pages from there. They are thin and it seems to work very well.