1.5 x 1.5 inch ziplocks. 1/4 full is about a dime bag.
And you know this how? By googling: amazon 1/4" x 1/4" dime bags?
Turns out there are also tiny ziplock bags sized to hold dime sized coins that collectors use.
So it seems like “dime-sized” bag could mean several things:
A bag that’s literally the size of a dime.
A tiny bag for holding a dime-sized coin.
A small bag that would hold a “dime” of cocaine — i.e. $10 worth (which would be a very small amount)
A smallish bag the size of what in drug slang is most commonly called a “dime bag”, which is $10 worth of marijuana, which is substantially more than $10 worth of cocaine.