You can use them without the tray, but it does help hold the paper in place to make the tracing process easier and more organized for the child. It also makes it much easier to gather all of the supplies needed on one tray.

@@learningmontessori Thanks for the reply, I'm trying to homeschool and figuring out what are the most essential materials.

@@caroc4327 Hi! I'm also homeschooling with minimum budget. I chose to save on the stands and buy the tray. The stands are bulky for a home environment (at least for mine) and expensive. The tray makes it super easy for the kid to hold the paper and the insets in place, especially if the kid is starting to use a pencil.

Any company who sells Montessori materials should have metal insets. If you are just purchasing them individually, Amazon has a couple retailers who sell them. www.amazon.com/Montessori-Metal-Insets-with-Stands/dp/B003Z4YAC2/ref=sr_1_2?crid=2ZG0K0LCMMF6P&keywords=metal+inserts+montessori&qid=1663341851&sprefix=metal+insets+montessori%2Caps%2C91&sr=8-2&ufe=app_do%3Aamzn1.fos.304cacc1-b508-45fb-a37f-a2c47c48c32f And here is the tray: www.amazon.com/Montessori-Metal-Insets-Tracing-Tray/dp/B00696PXH4/ref=sr_1_9?crid=2ZG0K0LCMMF6P&keywords=metal+inserts+montessori&qid=1663341962&sprefix=metal+insets+montessori%2Caps%2C91&sr=8-9