abn, yes, SVG file can be opened and edited in Illustrator. (SVG = Scalable Vector Graphics).
I definitely second the notion that effecient pattern making should be done in a Vector program (Illustrator/Corel Draw) rather than a Pixel based program, like Photoshop.
Assuming your patterns are for cutting your leather peices to a specific shape for production, vector programs allow for the easiest editing of shapes. I use Illustrator for cutting templates on a laser, but also by just printing the design on paper and cutting it out for tracing.
I use Photoshop purely for image manipulation for engraving.
Pixlemator is a good photoshop alternative if you are on a Mac.
That being said, you can use Photoshops vector shape tools to crate vector based patterns, but it's a real pain - extremely inefficianet compared to a vector based program.
Thanks
D
