To understand these differences I created this thread to help sort thing out.
On the
DDR's for example the 2013
DDR, when you see the images side by side you will see the differences:
Two things happening on this
DDR:
1. The raised devices will be enlarged in size.
2. The incuse devices will be reduced in size.
That is how doubled dies are totally different on these raised and incuse devices. They are opposites.










Same for
Machine Doubling. It does just the opposite on the different raised and incuse devices.
Raised devices will be reduced in size:



incuse devices will be enlarged in size:


So when looking at
DDR's on the
ATB Quarters, you will find them on the outer ring devices. The
DDR's are on the center of the design. So 70% of the enlarged incuse devices you find on these quarters are machine doubled, and never a doubled die, but
Machine Doubling. (they just can't happen on that area of the design.
Note
Machine Doubling on these cent design compared with the real
DDR incuse devices:

So the
Machine Doubling on the incuse and raised devices are just opposite each other.
So the true hub doubling on the doubled dies are just opposite. The raised are enlarged, the incuse are reduced in size. It took seeing this years cents to see what was going on with these raised and lower devices and how it also had an opposite affect on
Machine Doubling.
uploaded/coop/2016_1c_cent_MD_incuse_epu_devices_khasil_AAA.jpg


Hub doubling on incuse devices can also look different from die to die.


The VDB is incuse on the shoulder of the cents, so
Machine Doubling can affect the shape of these initials.
On raised devices
Machine Doubling can affect one side of the devices, while on the incuse devices they are affected on the opposite sides of the devices:

Confusing, but knowing the differences are there and how they are just opposites, helps calm the answers.
1. Doubled dies on
raised devices
enlarge the devices.
2. Doubled dies on
incuse devices will be
reduced in size.
A.
Machine doubling on raised devices will remove the contour flattening it into the devices,
make the devices smaller in size.
B.
Machine doubling on incuse devices will enlarge the devices by altering the incuse area pushing it, to
make the devices appear larger.
CoopHome:
Why are raised and incuse devices affected differently on the doubled dies and on Machine Doubling?