engrave qr code on granite

[victor belfour]

hi everyone just have a quick question

we are in the memorials business running a 35 watt vytek laser doing etchings along with sand blasting on black and different colored granites.

technology has changed! a customer has asked to etch a qr code directly onto a black granite memorial. Is this possible?
I actually etched the qr code onto a small test piece of black granite that is 1.5"x1.5" but it is not being read by anything.
Is granite too porous or 'speckly' a medium to etch qr codes? we printed the same code onto paper and a smart phone read it right away but could not pickup the granite at all.
From what i've seen online, other companies usually do it on a piece of stainless steel or ceramic and past it onto the granite. But i have not come across anyone physically lasering a qr code into granite.

any advice or experience would be greatly appreciated.

thanks!

[Mike Null]

You'll have to test it. The scanner can't read the code if there isn't sufficient contrast.

If the granite has a lot of white or gray then you may have a problem.

[Gary Hair]

You may have to do a two step blast, etch a square area a bit larger than the qr code to dull the surface and then blast the qr code and paint fill with some Lithichrome hilite or white to give you contrast.

Gary

[victor belfour]

hey guys thank you both for your quick responses and suggestions!

does the size of the qr code matter? the test granite i did was 1.5" square, there's space on the stone to go much bigger but I dont know if that would help to fight against the speckly nature of the granite. also i think it would look kind of well, tacky to have a portrait of a person on one side of a monument and a large qr code on the other side :/



You may have to do a two step blast, etch a square area a bit larger than the qr code to dull the surface and then blast the qr code and paint fill with some Lithichrome hilite or white to give you contrast.

Gary

thanks for the suggestion Gary but i dont think my boss will go for all this. It was supposed to be a simple granite etch but involving blasting and painting I think he wont go through with it. He didnt even want the thing on there in the 1st place. Anyone else out there successfully etch a qr code right into granite?

[Mike Null]

Victor

I think something even smaller would work particularly if you use Gary's suggestion of a color fill.

I'm bidding a job for use on rail car identification and found the 1 1/2" qr could be read at 3 feet which was their spec.

If your customer is a commercial firm using the same qr code why not suggest they use a 1" stainless steel plate cemented to the back of the monument.

[Chris DeGerolamo]

size does not matter, but you may have to add a border and invert the qr code in order for it to be recognized.