i've seen people put the Cosmetic PM in their PM and it does fit. I have tried it, but I didn't like how snug it fits inside. The PM canvas is very flexible while the base of the Cosmetic Pouch is structured and just a tad bit wider than the middle section of the PM. It can and will fit, but given some of the known issues with the PM I avoid using it in mine as I don't want to over stretch or force the canvas. I use my mini-pochette when I carry my PM, but there are times when I want to carry a little more and I'll use the TP15 and mini-pochette the same way Dleeds00 does.