Question about blank back printing plates/proofs

[DeepDiscounts]

I'm referring to the non-metal types that just have a blank back and are not numbered. Usually print run is /5 of each color (yellow, black, magenta, cyan). These could be found in the Father's day packs as well as in the redemption packs at the National show.

How are these actually used? Were they used in the actual production of the card or are they proofs/samples and they made the card off of another plate type (metal version).

[DeepDiscounts]

Bumping this one up to see if anyone knows. Reason I brought it up is many of these that I have seen have been dinged up (corner wear mostly) which leads me to believe that they were actually used somehow in the manufacturing process. If they were simply made and inserted into packs, the condition would mirror that of the other cards.