i was wondering if 4x5 film sleeve light proof exist ?

when unload the holders in order to keep shooting i usually store the negatives "all together" in the film negative light proof boxes (kodak etc..)and than i process ""all"" at once .
but whet if i have to process 1 neg at the time using custom timings ? how can i remove those negs from the holder while keeping track of "what is what" ,

so i guess that a simple 4x5 film single sleeve light proof would solve the issue (you could label each individually on the outside )

do they exist though?

googled it but can't find any

any other solution perhaps ?
how do you deal with this?

thanks!

g