shipping on different varients for an order?

Scenario: I will be ordering prints for images from two different places, one place prints posters, the other, canvas.

If someone adds a poster print and a canvas print to their same order, I will have to charge for shipping for both orders to cover my costs.

Is there away to add shipping to individual variants?

I realize as I write this, it may be too complicated, as it would require "if this, than..." coding that would hurt my brain. Because I don't want someone to be charged twice if they order the same type of characteristic, say an order of two prints. Then my supplier will only charge me once for both prints as they'll just put them in one tube.

But for two canvas prints, they may charge me twice... ugh, making a website is complicated.

Thanks for your help!

As far as the posters go, I'm not sure how many prints they can fit in a tube. But, I guess I could just limit the size of an order, but as an entrepreneur, that's usually what you don't want to do

Perhaps the simplest solution is to charge more after the fact after talking to the customer, how easy is that through paypal and hikashop?

Good call. Thanks for the thoughts.