Because I am sewing mainly for children, it is extra important for me that the materials I am choosing are perfect for their sensitive skin. I love to use 100% natural fibers like cotton and viscose. I always check before I order if the fabrics has at least an ecotex certification, which means that during the manufacturing process (for example printing) no harmful chemicals has been used.
For the custom printed fabrics, I usually order cotton poplin and organic knit, which does not contain polyester. The organic knit might not be as stretchy as a jersey containing a percentage of elasthane, but elasthane is basically plastic and apart from the fact that it can irritate the skin, when they end up in landfill they will never really disappear from the surface of the Earth. Meanwhile natural fibers can degrade in approximately five months.