Ok, so I’m about to cut the plexi… And I noticed in a bunch of youtube videos that there are some IR lights shining through at the edges (which makes sense).  I was going to make a little extra space on each side, then make a border on the bottom with something (wood probably) to cover them.

So I was planning on making the plexi a bit larger then the complient surface and rosco. 

Is it really needed?

But how big? 

I was going to go with 2 inches extra on each side… Mainly because then I wouldn’t have to make an extra cut… And it seemed like that would be enough.  But will I start loosing some of my light?

Thanks

I use 1.5 inches around each side.

I think 2 inches should be fine.

have extra border is a good idea. your plexi will be more structurally sound with more support.

i have 2” padding

Thanks for the input!  2” it is!

btw, these are some great forums!  Thanks EVERYONE!

Yes, I agree. Give enough space for each led ir light ‘cone’ to spread into each others, avoiding dead areas between.