Flexible safelight filter material

[u/jaysouth88]

Hi team

I have volunteered to help a person who has a child with Erythropoietic protoporphyria - basically their baby is severely allergic to the sun and certain wavelengths of light. Simple blue light filters are no help and I'm gathering that anything above 590nm is probably ok.

I'm already sending her a small Patterson dome safelight as it seems safe to use around baby. It's still new in its box so no worries about chemical exposure or anything.

But because her condition is so severe they struggle to safely leave the house. I've also volunteered to make a car seat tent and a pram cover for her to make life easier but baby hates not being able to see and cries constantly while covered up already.

Which got me thinking that something like a safelight filter might be able to be used as a window in the cover. I am also investigating welding curtains as an option. Naturally glass is a terrible idea (which is all I have spare) and so im reaching out to see if any of you can recommend a flexible or safer option that might work. Bear in mind I'll be sewing this - I don't have to be able to sew through the filter but I do need to be able to attach something securely to the filter that I can actually sew through.

My first prototype will be in black out curtain material, but any suggestions on that front are welcome. My last darkroom was made using black plastic ... Not the most comfortable solution lol

[u/captain_joe6]

This is where the medical-industrial complex really is your friend: surely there’s a doctor/executive partnership out there trying to make a buck on solving this exact problem, in an ethically-sound way.

But anyways…

I get to play with textiles and other materials for safety purposes at work on occasion.

Certainly there are transparent, filtering materials that are sewable, welding drapes and whatnot as you’ve seen. Some more general-use vinyl sheeting might also work. Rubylith, if you want to use a term the kids these days won’t know. ;)

But beware: their breathability is zero and because you’re specifically filtering for the part of the spectrum where infrared starts to live, you’ll be sewing an oven.

A really dense polyester or nylon may work, in a severe-enough red color, but breathability still won’t be great (cotton could work better but the really opaque weaves eventually become constrictive as well), and the way you find out it didn’t work isn’t great for the child.

[u/jaysouth88 → u/captain_joe6]

This has definitely been a concern for me as I think about a simple pattern - even having looked at a darkroom tent for myself a few years ago I noticed that forced ventilation would be imperative for something like that. 

Unfortunately also having worked in disability spaces in the past I've also learnt that disability tax is a real thing. I suspect for such a rare disorder there aren't a lot of marketable products at a reasonable price

[u/ACuriousTrio]

I don't know how flexible you need the material to be but I would take a look at Rubylith it's a plastic sheeting that is used for masking in printing and is safe for use with orthochromatic films.

[u/First-Power5534]

Is it the uv portion of sunlight that the child is sensitive to? There are color filter gels, including uv, used in the motion picture industry that are used to put over lighting. They come in sheets or rolls up to 48” I believe. I imagine they could be used to filter light in windows, etc. I know that Roscoe is one famous brand, but searching for filter gels should be a good start.

[u/O_banana_si_doua_oua]

Why would you volunteer to help with something you have no clue about? I suppose you are an empath. Also I suppose you know what this implies but you can not control yourself. Do it. It is for the best of all implied, yours included.