Rubber Stamp background issues

[Gregory Bolstad]

I am trying to make rubber stamps to impress clay with my Pinnacle V-series laser.
The problem I need help solving is the background (or floor in rubber stamp speak)leaves an undesirable texture which imprints onto the soft clay surface. How can I produce a rubber stamp which has the smoothest possible floor? Any settings anyone know of that I should look at first to tweak? Or running it different modes or something . I have messed with dpi and tried b&w mode which you would use for photos to no avail.
Thanks

[Dan Hintz]

Consider running a second pass of just the background slightly out of focus.

[Gregory Bolstad]

Dan mentions a second pass with background out of focus. I am not quite sure of his meaning. I am thinking it could be applying a gaussian blur to the file or perhaps lowering or raising my laser bed. Any clarification or ideas on this would be appreciated.
Thanks

[Josh Richard]

You would raise or lower your laser bed.

The boiled down explanation is that the laser beam is shaped like an X. When in focus, the beam is as small as it will be. By raising or lowering your bed, the beam will be a bit wider and have a different effect on the material.

For more info, you can use the search function at the top of the page.

[Mike Null]

If you decide to run out of focus be sure to protect your text with a white outline. Without it there is a risk that you may lose the sharp edges of the letters.

[Dan Hintz]

If you decide to run out of focus be sure to protect your text with a white outline. Without it there is a risk that you may lose the sharp edges of the letters.
Good point...

[Gregory Bolstad]

Ok, great that gives me some things to try plus answering my next question how to protect the text. So thanks very much. If I figure out some new things that work out for me I will be sure to post. If you have any other ideas or tips for me please let me know.
thank you

[Dee Gallo]

Curiosity makes me ask: what would happen if you did the first run out of focus and then ran the second pass in focus? Would the floor be smooth and the engraving be crisp? Or would it make no difference at all? Would this same concept apply to acrylic molds?

cheers, dee

[Dan Hintz]

Dee,

It absolutely applies to acrylic molds (though you have the focus/unfocused passes backward). You want the first to be in focus to get you the desired depth, followed by an out-of-focus run to smooth out the ridges. As long as you don't hit the sharp edges (resolved by what Mike mentioned), it turns out quite nicely.

[Dee Gallo]

Thanks Dan, good to know. I am still thinking about chocolate molds....

[Rodne Gold]

Forget about all the advise given to you so far , you are wasting your time:) (sorry guys not being mean here)
You will NEVER get a smooth surface if using the laser to hog out backgrounds , you can do what you want till you blue in the face , use any material you like , it just wont happen. Either you make the background ridges/roughness a "feature" or use another strategy. The only other option is to actually make the master with the laser , where you can use a smooth surface perspex or some other material and then actually use something like RTV casting silicon to make the mould you impress the clay with off the lasered master. Sometimes its just not possible to make the mould directly.

[Mike Null]

My experience would concur with Rodney's view. I have food grade RTV silicone on hand but haven't had time to test it. Still the master is the key.

[Gregory Bolstad]

We have had rubber stamps made for us by a bussiness and we are trying to get it as smooth as his. So while I agree there may be no way of having a 'perfectly' smooth background I still have not figured out what he does to his to make them so smooth that they do not mark the clay. He has an old Epilog.

So far I have been trying everyones ideas but still need to tweak the out of focus hack that has been mentioned with the white outline on the letters.

My best results so far have been to cut a fine dot matrix pass and then do an error diffusion pass. I will keep trying so shoot me more ideas if you think of something to try.

Thanks

[Dan Hintz]

I would consider cutting the stamp out of a thin sheet of rubber first, followed by the cut sheet being glued to a thicker backer and weeded (if necessary). This way, the backer is never touched by the laser and is therefore smooth.

[Rodne Gold]

He probably makes his stamps the polymer way. The way a laser works , works against you - it pulses and ablates material by "drilling" holes.

[Mike Null]

I have made two rubber stamps in 13 years. Both are in use but have very small striations on the base. (I chose not to make stamps or trophies when I started)

Have you considered using a palette knife to smooth the clay?

[John Noell]

I gotta agree with Rodney. If someone actually finds a way to make a smooth bed where the substrate is burned away I am ALL ears!!! I have tried and tried and I certainly can get acrylic a LOT smoother with multiple passes at different focus point and especially different DPIs - but truly smooth it ain't.

[Dee Gallo]

I'm with you, John, Mike and Rodney. I'd love to know the secret too...if there is one. Short of cutting out the stamp shape and gluing it onto a smooth base, I can't see making a stamp with a really smooth surface with my laser.

[Gregory Bolstad]

Wow,
Thanks for all of the input. It has given me a launching point in which to experiment.
The stamps that were made for me on the old Epilog laser in this guys shop( I watched him do it) creates a background which prints a smooth surface when it touches the clay.
I am positive that there is a way to do this I have over 300 stamps from this guy.
I am on a mission now to figure this how to reproduce this. To be clear, I can see some faint lines on his but it is so very fine that it does not leave barely a trace on soft wet clay and 'reads' as perfectly smooth.
I have not achieved this - Yet!
I will tell you how it all works out.
More ideas anyone?
Thanks

[Dee Gallo]

Wow,
Thanks for all of the input. It has given me a launching point in which to experiment.
The stamps that were made for me on the old Epilog laser in this guys shop( I watched him do it) creates a background which prints a smooth surface when it touches the clay.
I am positive that there is a way to do this I have over 300 stamps from this guy.
I am on a mission now to figure this how to reproduce this. To be clear, I can see some faint lines on his but it is so very fine that it does not leave barely a trace on soft wet clay and 'reads' as perfectly smooth.
I have not achieved this - Yet!
I will tell you how it all works out.
More ideas anyone?
Thanks

So I guess the question is can you ask him?

[Gregory Bolstad]

I may have to ask him. I did not buy a laser to go in to competition with him . I guess he may not be to happy about loosing my bussines. I am usally pretty free with information I know. I have a few more things to try.
Would you take time to teach a 'former customer' ?

[Dee Gallo]

I would, but that's me. Most people would see that as cutting your own throat. I don't feel like anyone can compete with me since my niche is pretty specific and it takes a lot more knowledge and skill than just one bit of information, but I suppose if someone was going to go head to head with me, I might hold back.

It would be worth a try, in my opinion. The worst that can happen is you apologize if he is insulted.

[Bill Cunningham]

I get approached to do this a dozen or more times a year.. And you can't do it.. The stamps that can do it are either polymer, or vulcanized rubber. More usually vulcanized rubber now. The vulcanized stamps are done in a matrix mold which is created from a hard polymer master, or usually a 11 point mag die, called a cut. These are also used for hotstamping. The live rubber is vulcanized with heat and pressure in a hydraulic press which insures that the non raised portions of the stamp are smooth. The person trying to press this into clay will wet the surface, gently press in the stamp, the remove it very carefully. If the clay is wet enough, the clay will not stick to the 'smooth' surface. The unfortunate part, is vulcanized stamps (which 20 years ago were the standard) are now too expensive for most folks that only want 'one'. Vulcanized 'art' stamps are now only mass produced, usually in china.. I still make them for stamps that use acid or alcohol based ink, which eats polymer. But I make them on the laser unless they need a bunch the same on multiple runs, then I use the old methods with the vulcanizer press. I think I've used it twice now in the last 7 years.