Dual pocket outers in crystal clear sleeves from vinyl storage solutions in Canada. The new dual pocket gatefolds are superb as well. Their inner sleeves without any writing on them (as opposed to Mofi etc.) are another wonderful item they carry. About 1,700 records.
I've sleeved my albums since my teen years in the 80s. Changed everything to VSS sleeves about 3 years ago. So worth it.
I like the dual sleeves with single flap. The flapped side receives the outer cover bottom up, flap down. The no-flap side gets record in inner sleeve plus printed original sleeves, lyrics sheets, booklets, hype sticker, artists's notes etc. To get a record out, a grab the record by a bottom corner, and turn it upside down. The record slides out into the waiting palm for the edge of the record, finger on hole.
In theory, dust could settle into the top crack, but as our home is reasonably clean and records are in shelves with top, I have not noticed any problems.