On the table games you will notice a space between chips in the rack. They are spaced every 20 chips with a lammer. Example 20 whites= $20, 20 reds=$100,20 greens=$500,20 blacks=2,000. On a crap table all stacks in the bank are 20 chips high and no lammer is used. This makes it easy for the eye in the sky and Pit Personnel to read the rack, for a count.
Most other Casino's use this system also for the same reasons above. Lammer's in most Casino's now are clear plastic. Lammer's in some smaller Casino's are used by dealer's to keep track of the table drop for Pit Bosses.