These dresses are super stretchy, comfortable and hip. The strap does not dig in and is adjustable with a button to fasten. Size small fits 1-2 years, medium fits 2-3 years, and the large fits 3-4 years. The fabric is 96% polyester and 4% spandex fabric which allows a 4-way stretch, it's lightweight and stretchy with a super soft cotton-like hand. The patterns are crisp, bright colors that wash well, all pants are pre-washed. Dresses are handmade in Canada and the fabric is made in the USA.