Blackout blinds

I just came across these. No affiliation, but it looks like a decent solution to black out darkroom windows. Made to order, I would inquire as to how totally light-tight they are before ordering. https://guardblinds.com/products/guard-total-blackout-blinds

Hi, I have them. They seem perfectly fine at night. But if they are subject to direct and full sunshine, there is a little "glow" to them. I was loading film into tanks yesterday, when midway through I noticed the glow. I didn't notice any evidence to the eye of clouding on the film, after developing, but wonder if there could have been a slight fog resulting.

When I was living in an apartment and doing darkroom stuff in a spare bedroom, I took foamcore panels (white side facing outdoors, black side facing inside) cut to closely inset fit the window opening and block most of the light, then overlayed the window opening with a sheet of blackout cloth, and that gave me a dark enough room to print color even in daylight hours!
Supplementing this product, foamcore inset would alleviate the issue of the aforementioned 'glow' during daylight!

Thanks for posting. It looks like a great solution for me.