How to keep textures from tiling in Paintshop?

Until I get a new computer and can download a graphics program (probably Gimp, but maybe Corel Paintshop), I want my husband to make some shirts for me on Paintshop. He has the templates all done, and I have some textures. I'm not really a free-hand artist, so until I can actually dig into a program myself, I'm using textures I've purchased.

The problem is, when he makes a swatch and applies the texture to the template, it takes forever to get it sized correctly. And if the texture isn't seamless, forget it. It just tiles which doesn't look great on a shirt. We're both really new to this part of clothes making, and there has to be a way to get around this and make the texture look proper on the shirt/pants/skirt...whatever. However, we just can't figure it out, and he's spent tons of time on tutorials that haven't really seemed to directly answer that.

I know that one of your knowledgeable people will have an answer. Unless I'm the only clothes creator on SL that doesn't hand make my own textures?? I hope not!....lol

Is there a way to get the texture *fitted* correctly? Please keep in my mind, I'm new at this, so technical terms are just going to confuse my poor, tired brain. Probably you should talk down to me a bit for this. Thanks!

I think you need to upload a picture of the problem. Otherwise, there are a million possible answers.