The carpet padding is not going to perform the same way as upholstery batting. In this case only one solution exists.
I've suggested calling your local upholstery stores and purchasing your small amounts in cash. You'll pay a small premium over the per-foot price for a large roll, but it is well worth it to not need to store a roll of the stuff that is two-feet thick.
For some reason etchings of dead political figures on paper can be exchanged for a variety of goods and services which would not be available to one when using a piece of embossed crosslinked hydrocarbons with an affixed hologram. I believe this is part of the appeal of crypto-currencies.
While one can layer the batting, it may be easier to obtain the right thickness.