this is what jay from jtech said in an email.
its a bit hard to follow haha
Using laser etch it all has to do with pixels. Your pixel size in laser etch is your laser spot size. It is set in the “travel per pixel” setting in laser etch. It defaults to 0.1mm. You probably can bump this up to 0.2mm and you will notice your size of your image is now 180mm.
You need to focus on your final engraved image size because that is what you are going for.
Your image you start with is 10” x 10” and your resolution is 72 pixels per inch.
Your Travel per Pixel is set to 0.008” *(this is 0.2mm in inches).
You will get an final image of:
720 * 0.008” = 5.76” x 5.76”
If you want the final image to be 10” x 10” as well, then you need to start with an image that is 17.36” x 17.36” at 72 pix/inch. ( (10” / 0.008”) / 72) )
You have to use the “travel per pixel” size because that is your size you are drawing with. If this number is too big, then you will see “lines” in your engraving. If it is too small, you will “overlap” your engraving.