All you need is paint,tape and sandwich bags.
Squirt your favourite colour into the sandwich bag or add two different colours for the older children to investigate colour mixing. Close the zip lock up firmly. Use tape to secure them on your glass window or door.
Think about the ideal height for your child when you are securing it on. A 7 month old may love to sit and play while placing it higher for a 9 month old will encourage him/her to stand up. This also works for siblings. I placed one quite high for Tara so her little brother was unable to "help" her do her work :)
Great for little hands