What I have done in the past and helped others with is to use a thermal printer, normally a Zebra model and the Bartender software.  The software can connect by ODBC to Sage 100 and pull the data you need. You can even create a button with a script so the user while in Sage 100 can click the button and the label comes up and you print it out. Getting Crystal to print small custom labels is a pain. 

What I have done in the past and helped others with is to use a thermal printer, normally a Zebra model and the Bartender software.  The software can connect by ODBC to Sage 100 and pull the data you need. You can even create a button with a script so the user while in Sage 100 can click the button and the label comes up and you print it out. Getting Crystal to print small custom labels is a pain. 

I definitely agree about CR printing to Zebra labels being difficult to get working properly.

Be cautious of thermal labels if your stock might be exposed to heat / sunlight... but there are other options still within the Zebra family (which seems to be the most common brand for industrial label printing) if that is an issue.