Now this is just a guess, since I haven't used weight for my shipping calculations; but, I believe when you generate your PayPal "Buy Now" OR "Add to Cart" button; and you select "calculate shipping by weight" mode; you enter a price/lbs. in the chart,(at PayPal).

Then, when you have entered all the details that PayPal allows; they will create the coding that generates the button on your site. You'll copy/paste that code into an html box on your page in BV.

Now, you have one button with all the purchase details for that one item.

You can now paste that code into as many buttons as you need. Then go into the html box's properties and change the codes to set a different code for the rate or weight for that item, etc.

One thing you can't change in that code is the business name code.

Now this info is really just an educated guess, because I have not set one up for weight shipping calculations. You should go to PayPal and generate a payment button so you can see what the code is that it generates for shipping by weight. You can make many buttons at PayPal, so don't be shy about trying it! Infact when I get done with this post; I'm going to PayPal to set up a button for weight shipping to see what the result is!