Depending on what you are calling doubling:
This
Machine Doubling:

Note how the devices are reduced in size by the MD (Flat, shelf like missing the contour on the devices)
Note on the
Machine Doubling the outer areas of the devices are affected.
Here is an couple of examples of a doubled dies:

Note the affected areas? They are showing spread on the centers of the devices. Not on the outside edges except when notching happens. Not how much wider they are.
Machine Doubling is caused by machine malfunction. (these are real common)
Doubled dies are enlarged/doubled by the hub that creates the die. Thus a doubled die is called a doubled die, because the doubling in on the die. (Premiums for these)
So scroll and compair the size differences between the two sets of images. Then you will be what is reduced and enlarged.
Edited by coop
12/14/2019 8:46 pm