MOFI sleeves and nothing else. Ultrasonic cleaning is snake oil and actually makes records sound worse.
^^^ and this is how audio myths are spread....
nitty gritty until such time as the Livermore Lab rats make ultrasonic less hazardus than three mile island...after that, even if it came in a QRP i use a new virgin MFSL sleve ( i donate the dirty QRP to my destitute but wannabe poser audiophile brother in law - thereby virtue signaling my recycle everything mentality )
no outer sleeve meets my standards for anti-static and hubble grade optical characteristics, so paper album covers are free to snuggle damage each other......
My apologies for all those that replied. Between work and not feeling so great this week I forgot to check in on my question.
I appreciate all the replies and links. Seems like there are many good options - especially if the inside sleeve is just paper. I had my eye on the. MoFi options but like some of the others suggested here as well.
I replace plain paper inners with poly/paper, be it MoFi or something else. I've never understood the upside of MoFi sleeves over regular, decent quality poly/paper sleeves however.
Outer sleeves I've never used. My oldest records (35+ years) can generally still be comfortably graded NM/NM and in any case I've never sold a record in my life, only given some away.