The print function for shipping labels will usually default to a standard 8.5 by 11 format. However, sometimes you will need to print a smaller label. The following screenshots should help illustrate how to change your label's print size:
From the Print Label dialogue screen:
Then click the Advanced button located towards the bottom right.
Under Paper/Output > Paper Size, choose PostScript Custom Page Size as shown.
Then, change the label dimensions to suit your specific needs.