These silicone tray liners are used to prevent food from sticking to the trays. One can also use butcher paper if desired.
Small sets include four liners ($30)
Medium sets include five liners ($35)
Large sets include six liners ($49)
X-Large sets include seven liners ($80) - available in Oct, 2023
Note that the picture shows a liner placed inside a tray. The tray itself is not included.