Often people try to get away with lower postage rates by incorrectly stating the package weight when printing pre-paid labels at home. Not a good idea. Don't tempt fate with the US Postal Service. The USPS routinely performs random checks. If they find one or more of your packages has the wrong weight, they will start checking your packages more frequently. In many cases they will add shipping and try to collect from the recipient, which never goes over well. Sometimes they send it back to you. You may even get a visit from the postal inspector. Mail fraud is a Federal Crime.
Another shipping tip is to use stealth shipping or select the option in PayPal to hide the shipping cost. Doing so may avoid potential problems with unhappy customers.
The simplest solution may just be to purchase a postal scale. We use a Digiweigh Postal Scale for packages up to 50lbs but any postal scale will work. The office stores have them but they are way overpriced. Of course you can check them out on eBay and they will be cheaper.
Try these searches:
Postal Scale
Digiweigh Postal Scale
Shipping Scale
