*Is there a way to assign custom shipping price for different sized items? I sell paintings - various sizes from small to large. Using the weight and size tool doesnt seem to work as canvases are usually the same weight if they are a similar size. Is there a way to assign a rate to large works, medium works and small works that doesnt allow the customer to select it at checkout? I am concerned people will just pick the cheapest shipping price when realistically will cost me a lot more. * a newbie to ecommerce by the way!