Is it possible to:
Use Stripe as Integrated payments option?
Control opacity of artwork?
1) not directly, no. You'd need to set up different products for each image size.
2) That can be cone via WooCommerce
3) Sorry, no or only of WooCommerce supports it?
4) that is no problem.
Thanks Jonhy. I had to buy another product designer because I needed "price according to image area" feature.
Questions: can I buy your plugin to use your "product layer scheme" (t-shirt multiply shadow overlay layer mostly). and the t-shirt displayed on the plugin I mentioned?