How to stop or slow down slime mold growth?

[Anna Sagatov]

Hello!  I have a slime mold art exhibition coming up and my slime molds will be on display for a week (in drawers, out of the light of course!).  I was hoping I could get them to retain certain shapes by replacing their oats every day with new ones in the exact same places, but they keep getting bigger! Does anyone know how to slow or stop slime mold growth?  I was thinking about possibly drying out my agar plates so they dehydrate, but I'm afraid that might push them to spore?  What about cold temperatures?  Let me know what has worked for you!

Anna