I use an art portfolio book (https://www.amazon.com/dp/B097268MQK/ref=cm_sw_r_cp_api_glt_i_EET5P4VSKCW8CGQ7H3DZ?_encoding=UTF8&psc=1) to store my finished projects until I can frame them but I don’t see why you couldn’t store your WIPs in it as well
So I got this art display portfolio (Sooez Art Portfolios 11x17, Large Portfolio Folder with 30 Pockets & Black Inner Sheets, Display 60 Pages, 11 x 17 or A3 Presentation Book for Artwork Storage, Binder with Plastic Sleeves for Artist https://www.amazon.com/dp/B097268MQK/ref=cm_sw_r_cp_api_glt_i_RFQKHHSCMFQEKFAWT3JF?_encoding=UTF8&psc=1) and it is great for storing my finished pieces until I can frame them. I like it because they’re stored but I can still look at them without having to pull them out of boxes in the closet or whatever.
I bought myself a portfolio to put the ones I really like in. The rest stay in the sketchbooks I glue them into.
https://www.amazon.com/dp/B097268MQK?ref=ppx\_yo2ov\_dt\_b\_product\_details&th=1