200 pcs Brown Kraft Paper Merchandise Gift Bags Shopping Sales Tote Bags 6"x9"

Are these flat merchandise bags? Or do they have a gusset (extra flat piece on the bottom to help the bag stand on its own)?

How many ounces will this bag hold?

Would my artisan soap bars fit in these bags? The 3 sizes measure 2 7/8" x 1" x 3 1/2" and 4 1/4" x 1" x 2 3/4" and 2 7/8" x 1" x 2 3/4"

Are these truly 6" wide? i am going to use them as mailing envelopes and usps only allows an envelope to be 6.125 for first class postage.