If you’ve been paying attention much in the past 10 years, you already know that Invisalign in Wakefield offers a way for adults to straighten their teeth without having to wear metal brackets and wires for a year or more. Invisalign is clear and practically invisible when worn. But — what are those trays made out of? Keep reading to learn more about how the material of Invisalign trays keeps them sturdy and able to shift your teeth around.