Mounting Rails?

[Ldireprophil]

I'm looking to mount 3mm ACM and PVC corporate sponsorship signs flat against the basketball gym walls in my local high school. What is that hardware called and where is the best place to get it?

TIA

 

[Devon19515]

French Cleat

 

[Zac]

Highly suggest double sided tape over a french cleat in a gym environment. They are going to get nailed with more balls than my ex.