How to accept and ship international orders

[CM-Art]

Hi! I would appreciate some assistance and input, please. My online store currently accepts U.S. orders. I'm looking into accepting international orders. I'm currently using the Square free plan.

To accept and ship international orders in addition to U.S. orders, can I use the free plan?
Currently I ship all U.S. orders with a flat rate. I ship art prints in flat rigid mailers (approximately 11"x14", or in tubes).

If I were to accept international orders, I'm perplexed by how I would set that up.
I have heard that cost for shipping international orders is expensive. Plus it sounds like there are extra things to know (would I need to know about customs? VAT? anything else?)

For figuring out shipping cost, what I've done before is measure and weigh everything, and include cost of shipping materials and some for my time to fulfill an order. I'm wondering if I'm missing a simpler way to do this?

I'd need to figure out if it would cost less for me and the customer if I did flat rate or something else (and what that best option is for my situation), what service to ship through, or any of the rules and paperwork that might be part of fulfilling an international order. Thanks much!

[JK_Fiber_Art]

International Shipping is a challenge as there is extra paperwork (forms, etc.) and cost.   You may want to checkout some of the Shipping Apps that can work with Square - it's much better than trying to navigate the process on your own.

[CM-Art]

Thanks. I'll start there.