I just like using the flat rates, I print the label off of the PayPal website, it gives you a free confirmation number and fifty cents off the going rate. I one time had a gal inthe PO tell me that I did not pay enough and owed more postage before she would take it. I just simply took it to another PO and asked if it was true, nope, paypal gives a discount to their customers and it is all paid for.