View Full Version : can this pic be engraved in acrylic?

Craig Hogarth
06-06-2007, 2:59 AM

I'm trying to engrave this picture on acrylic, but just can't seem to work around the shadows. The faces just come out as one big blob. I've done others today, so I know my settings are right. I don't know if this can be fixed with paint or photograv.

Any advice on this would be greatly appreciated.

Frank Corker
06-06-2007, 4:21 AM
Try this at 300 dpi at your normal raster engraving speed. The image is flipped horizontal. If you are going to engrave on the front, wait until you have it in Corel and flip it back. I have enlarged it to 5" of height

Brian Robison
06-06-2007, 8:23 AM
How did you do that Frank?

Lee DeRaud
06-06-2007, 9:34 AM
No offense, but I wouldn't even attempt to engrave that picture on anything until I had gotten rid of everything in the background. Remember, you're only working with two colors by the time it goes to the laser.

Craig Hogarth
06-06-2007, 12:15 PM
Thanks Frank. I wasn't expecting anyone to do it for me. :)

I attempted it about 20 times and couldn't get it to work. If you don't mind, how did you get it done?

I'll post pics once I get done with the final project.

BTW, Frank, how did you know that I needed it at 5 inches?

Frank Corker
06-06-2007, 7:48 PM
Normally I do my through photograv but because I don't have the ins and outs of your computer I did it with the method given by Rod Gold using Photoshop. It's very effective, especially if you don't have or can't afford photograv (which incidently needs a HUGE upgrade to bring it into modern times) then it can be ideal.

1) Convert to 8 bit greyscale (image/mode/greyscale)
2) Resize the image to the size its getting engraved at using 150-300 ppi (150 for less detail) (image/image size)
3) Bump up contrast and brightness about +25 in both cases - you dont want the pic to be insipid areas of medium grey. image/adjusyments/brightess-contrast)
4) Heres the VITAL part - use unsharp mask at 500% and a radius of 3-5 pixels - threshold 0 - this will exaggerate edges radically , but thats what you need. In fact you can do this and then STILL add another unsharp mask at 150 % , 1pixel and 0 threshold AFTER the 1st unsharp if you want even more edge detection
(filter/sharpuen/unsharp mask)
5) Convert to a bitmap using 125-150ppi and a diffusion pattern. (image/mode/bitmap)
5) laser

I converted it for you so that when you try it yourself in Photoshop, you will have something to compare it to and see if it was right. It helps the learning curve. Lee is right about the background, with a bit of skill it is possible to remove the whole background and leave the people, but it's not always the case and often leaves the image 'wanting more' which is why I left it alone. The people you are doing it for quite often want the background in.

I knew it had to be 5" because the current size is way to small to even be noticed. What can I say, some people have it :D

Dave Jones
06-07-2007, 1:09 PM
One thing you can do to make people stand out in an image, without completely removing the background is to create a new layer on top of the image and then using a paintbrush (soft edges) paint white all over the background.

After drawing it, use a small eraser brush to go over the people and make sure none of the white got on top of the people.

Then adjust the opacity of that layer so it is just lightening the background a bit but not completely covering it up. That makes the background engrave lightly, with all the detail, etc... but makes the people "pop" out of it.

Craig Hogarth
06-07-2007, 1:38 PM
Is there a way to do it in paint? I don't have any versions of photoshop.

Brian Robison
06-07-2007, 2:14 PM
Hi Craig, yes it's the same method I'm using.
Copy paste into Photo Paint.
Image/ Color Mode/ Grey scale/ (8 bits)
Image/ Resample (to the size you need 300dpi)
Image / Adjust/ Brightness, Contrast, Intensity (+25)
Effects/Sharpen/ Unsharp Mask ( 500%, 4 pixels, threshold 0)

Hope this helps. It worked for me.

Frank Corker
06-07-2007, 2:15 PM
You must have Corel on your computer which is much heavier duty art graphic package! Paint is about the most basic thing on windows and just as useful unfortunately.

Scott Shepherd
06-07-2007, 2:19 PM
Appears to also work using those steps in Photoshop Elements, which is about $80-100.

Thanks for posting that Frank, you said it wasn't your technique, but I hadn't seen it in Rodne's posts, so thanks for reposting it.

Much appreciated.

Brian Robison
06-07-2007, 3:17 PM
I wish i could figure out a way to fix it in Corel Draw and not have to take it over to Photo Paint or make it a bitmap.

Barbara Buhse
06-07-2007, 6:36 PM
I get photos like this all the time from customers...
I use Microsoft Picture It to edit the photos, its inexpensive (around $60) and really easy to use...
The steps I would take with that photo...

turn it to black and white...
increase the contrast (most photos I also increase the brightness, but probably wouldn't for this one)
cut out around the top of the people (yeah, have to do this by hand, but Picture it makes it really easy to find the edges) to get rid of the background...
then I would blur the bottom of the photo a bit to soften it.

Then follow the steps in Corel draw (make 8 bit greyscal bitmap, etc) and photograv it to the proper material.

Brian Robison
06-08-2007, 8:50 AM
I just played with another picture. I do coats of arms on marblized brass plates on walnut plaques. It's really tough to make them look right. I found all the settings in Corel Draw without having to import and export into other programs. I hope it works out OK.