Honey, I Shrunk The Bags!
This bag started out measuring 16.5" x 9" with the base 13" x 6" - it felted down to 13" x 6.5" with a 10" x 5" base. In the following photo, you can see how tightly the garter stitch bottom felted. The completed bag is just big enough to hold a 3½ ounce skein of yarn which makes me think that it's not going to be of much use as a project bag. I may try to add a bead closure to fancy it up and use it as an alternate purse.
The second bag was the one with the shoulder straps. It started out measuring 15" x 11" with a 14.5" x 8" base. The handles were about 18" measured from end to end and when placed over my shoulder, the bottom of the bag hung at hip level. Coming out of the washer, the size had shrunk to 12" x 7" and the base to 10.5" x 6". The handles, which were 9 rows wide, felted into soft ropes. They still fit over my shoulder, but along with the bag are enough shorter that the bottom of the bag hangs at waist level.
I like the overall effect of the more felted bags, but I'm not sure about the ultimate size. Both of these are more purse size now than what I need to carry a project. The next bag is either going to be knit much bigger than I want the finished size or I'm not going to felt it as long. (The elderly cassette tape added for scale purposes is the Grateful Dead's (Best of) Skeletons From The Closet from 1974)