Skip the clear tape, and buy several thousand label sheets. Look for "UPS Labels". These are "two-up" on a 8.5x11 sheet, and are desifgned for the Paypal USPS/UPS labels. No clear tape. Print-peel-stick.
The labels are cheap. I got 3000 sheets (6000 labels) for $10. You will use one full sheet per item shipped, so if you buy 2400 labels, it's for 1200 shipments.
Example auction here:
http://cgi.ebay.com/2400-SHIPPING-LABELS-UPS-USPS-CLICK...QQrdZ1QQcmdZViewItem