Token Issuance: Relationship between description length and BTC required

Dear Community,
I am new to counterparty, but am interested in better understanding how the BTC transaction fees relate to the length of the description in the asset being issued.

Is there a maximum number of bytes that can be stored in an amount of BTC? So if the description exceeds a certain byte amount, more unspent BTC transactions are needed to store the data?

I have tried issued various test assets with varying description lengths on the testnet, but am not sure of the true relationship to the underlying BTC op-return data and required BTC balance.

A big thank you in advance for any tips!