Sleeves (and a GIMP question)

I was making one of my first experimental pieces of clothing over the weekend and ran into a bit of trouble. It's a very simple robe -- nothing fancy yet -- and I was discouraged by the sleeves. I filled the pattern fully into what I thought I understood to the the seam allowances on all pieces, yet when the the robe was worn by my avi (a curvy well-fed girl) and a friend's (smaller, sleeker furry) the sleeves looked like the incredible hulk and gotten to the top! Neither the shoulder nor the arm seems were close to meeting. Did I do something wrong, or do I just need to extend my texture well beyond the edge of the template? (Note: I'm using Chip Midnight's templates as I find their detail to be much easier to work with.)

Also, a GIMP question:

Is it possible to import my fabric textures into GIMP so I can just fill selected areas with them? If so, can anyone tell me how to do this?

Many thanks for your help!

good question, since I use GIMP as well. Wish I knew, I'd start making men's clothes, due to the almost total lack of them.

Open the texture normally, then save it as a GIMP Pattern file .PAT I think, but it has to be in the correct folder too.

If you are using one of the latest versions of GIMP (since it is coming with the instalation package since 1.4) there an quick way of doing this:

Open the fabric image in GIMP
Go to your Script-Fu menu, Selection, To Pattern.

If you are using an older version, you can either go to the GIMP side and update or just search for the script and install it.