Acrylic engraving - the frosted look

I’m wondering how everyone handles the frosted look on their acrylic engravings.i.e.: I am using cast acrylic, which after engraving leaves a much more frosted white look to it, but - on larger lettering and graphics instead of the nice frosted look I see on many other things, it tends to have a grainy look to it where one can see the scan lines and many times the pulse dots of where the laser pulsed.I had read somewhere about running a job a second time out of focus, or to create black areas over where an image is engraved and run it at 100/100 a bit out of focus, but I haven’t found the right way to do it yet. I’m sure others on this list have found the solution to this little problem. I am just hoping someone would be willing to share =)I’m not having a problem with the initial engraving or anything like that, just of giving the engraving more of a solid frosted look rather then the scan lines.