McCall's 6588 has 2 versions of different market bags in the pattern, and I have made both. This is the big, boxy one and it fits my sewing machine very nicely! The 2 inside "bottle" pockets hold the pressure foot, electrical cord, extension cord, little box of my bobbins, etc. very nicely - away from the machine so it doesn't get all scratched up. The outside pocket holds my plastic container with that holds my pins, scissors, measuring tape, etc., etc. It really is the perfect bag for keeping all my machine components together and ready to move around the house or go on a little car ride at a moments notice! When I am done sewing, I put everything back in the bag and slide it all onto the closet shelf. I do not put cardboard in the bottom of my bags so I don't have to worry about the weight of the machine bending the cardboard.
I used extra sturdy fabric for the outside. As you can imagine - it is a bit heavy with the machine, but the shoulder strap is extra wide for comfort and it isn't like I am going to walk for a mile with my machine slung over my shoulder! I make ALL SORTS of kinds of bags and use them for many different things! My husband is always amazed by my never ending "need" for various and assorted bags!