The 40x20 size sits perfectly on 3 ml vials. I chose a model that offers 300 dpi output and can handle red plus black with the right stock, and holographic options were not important to me.
I'd like to know what label printers others here own and which they suggest. A basic model seems too limited for my needs. I want to clearly mark each peptide vial with the compound name, the amount in IU or mg, the expiration date, and the original batch number. Also, which label dimensions work best on 3 ml vials?