This pattern was written for Adult Female size. You will need to get 1 pair of felt insoles for the foam cushion which is in between the 2 soles or real foam inserts. These foam cushions or felt insoles can be found at most footwear stores, I also get them at the Dollar Stores and you can order them from Etsy Shops. I have only made these slippers using the T-Shirt yarn made by Bernat Home Maker Dec and I have not tried the Bulky yarn, but I would recommend you use the Cotton Bulky. If you have any questions, please do not hesitate to contact me. Thank you for your purchase :)