So, you're saying the black thread would show against white lining - inside? Neatly done, I would think that would be fine. Who looks at the inside of someone else's mask. I understand you wanting it to be perfect using someone's beloved pajama fabric, but I at least would be happy with it.

I have a couple of masks with white inner lining. I really wish someone would remind me to wipe off lip gloss before putting those on. On the upside, it at least has me washing them in hottest water, lingerie bag in my machine.

Here's a mask I made with black and white fabric and black thread:

The elastic is one continuous loop that is tacked down on the right side only, so that it can slide through the channel on the left side, making it easier to adjust and therefore more comfortable. It is also easy to wear around one's neck when it is not necessary to cover the face.

I made a cabana jacket with this same fabric, but I used white thread for that because the lining is white.

What kind of fabric are the pajama bottoms? I hope they are not flannel. Are they black?

You can order white thread from Amazon and get it fairly quickly - generally two days, if you have Amazon Prime.

One thing I have lots of is thread!

The only black seam visible on the white fabric will be on the side channels for the elastic or ties, and it looks fine.

The pajama fabric is one of those man made fabrics that pills. It's in washing right now or I'd look to see what it is. My backing fabric would be a solid white with no pattern. I think I can sew it neatly. I'm trying to get this done in the next 24 hours without shopping. That's why I'm attempting to not go to a store or buy online.

If it were for my family, it wouldn't be a big deal to me. It may not be a big deal to the person I'm making it for either. I don't know. He had seen the fun masks I had given his daughter and asked her to ask me to make him some.

At this point I wouldn't worry too much about appearance. The mask will do its job regardless.

I think it would be fine. I understand about trying to avoid a trip to the store.

I think it would look great! That is really nice of you to do this for the man,

and I am sure he will appreciate it whatever you decide.

Yes, it will look perfect. I had the same situation today. I had another request for a mask and I had no matching thread. I used zigzag stitch to make it a decorative stitch. I have no fancy stitches ,as my machine is over 50 years old. She sews beautiful. Person I made it for was very happy. I have made many mask to give away , great thing is my stash of material and thread is greatly diminished. That’s a good thing for someone my age. So , go for it. They will be very happy with your results.

I made a mask today with a solid cream lining, stitched with black thread. It looks fine. Thanks for the fabric Donna! Note: It has a layer of non-woven fabric sewn into it as a filter.