OK so I found another Boxy Bag pattern with french seams. A little tricky but it turned out great. A tad on the large size but I do like it.
I made mine larger than the pattern stated, mine 12 x 17 (hers is 11 x 9). You can find the Boxy Bag with concealed seams HERE.
Check out the inside ... no seams ... clean lines. I love it.
I also added a handle to my bag, 9 1/2 inches long.
AND I added a tab next to the zipper to hold onto.
Again the Thread Holder pattern can be found HERE.