Light control (flowering)

I'm making a separate flowering room in a sliding closet. The sliding doors are rather poor on blocking light (can't blame 'em, weren't designed for ganja growing)

I'm looking for a cheap way of blocking the light for during dark period.
A curtain could work, just concerned about light creeping around the edges/corners. HD or Lowes or Waly-World solutions most preferred.

I want ease of use.

Thanks!

Mylar from the emergency blanket found in the camping section of wallyworld?

Well duct tape is hard to beat. That and some opaque plastic should do the job. I've done all kind of things for light proofing, just make sure that the space isn't airtight too...

Duct tape is used, but not on the doors. Gotta get in to check on and replenish water/CO2.

Air tight isn't a prob. Intake /exhaust fans installed.

The opaque plastic is the trick. (then attaching on edges. I guess velcro could work.) Them blue traps are far from opaque.

I might have a look at the emergency blankets at WalyWorld. Gotta run over there anyways.