Weight-based shipping when more than one item can go in a package. (Packaging weight)

New to Squarespace and online commerce.

I sell art prints. They don't weigh much. The weight is mostly in the packaging itself. So, if I ship 1 print versus 4 prints, the weight doesn't change much, but I can only assign weights to the individual prints. I can account for the package weight in the print's weight, but then the package weight is multiplied if a customer wants 4 prints making the shipping way higher than needed.

Is there some clever way to handle this?

Thanks!