Ok I have a question, that might be slightly off topic, but it does involve dimples.

So I was reading at a site about playfield production and saw a list of the process in making a playfield

This is the site - http://www.hsapinball.com/HSA_PINBALL/PF_Production.html

and this is the part that leads me to my question

4.Stamping the dimples into the completed playfield. Most of the pinball companies had the dimpling presses.

What, exactly, is that referring to? Steve Kulpa saw a picture of my playfield years ago when I was talking to him about the swap process and he commented that there weren't even any dimples on the PF. I didn't really regard it at the time, but now I wonder. Reason I ask is that I am trying to figure out who manufactured my Fireball II playfield and this is all that is on the bottom edge of the field

208_0849 (resized).JPG

http://www.pingamejournal.com/stern/archive.php

"These presses put dimples in the top and bottom of the boards much like a classic pressing machine applies heat from the top and bottom to press clothing. These impressions are used by line workers to assure accurate placement of various playfield parts."