Can I ship a vintage encyclopedia set using media mail?

USPS is kinda vague on what types of books can be sent using media mail..

As far as I know and understand printed material or recordings is all fair game. I wouldn't ship an encyclopedia set any other way. To expensive. I have shipped Records, books, dvd's and cds with no issue. Half the time when dropping it off they ask what it is, but have never given me any problems. Media mail is the only mail they are legally allowed to open and inspect without proper cause. Just because it is so much cheaper, people try to game the system.

I don't think I'd have a problem. I just wasn't sure because the website says "certain books and documents" and lists examples, none of which would apply to me. I have the set up on ebay now as local pickup, but if I can ship media mail, I'd open up so many more opportunities.

hell yes !
media mail was intended for educational materials , especially books

Yes you absolutely can use media mail.

USPS is kinda vague on what types of books can be sent using media mail..

I read their requirements a month or two ago and one of the things I got from it was that there was to be no advertising in the media sent. This would exclude magazines, but one person on the eBay forums indicated that many CDs, DVDs, etc contained advertising and what was the difference.

I often buy specialty hobby interest magazines for selling on eBay and most of the time they are older (maybe from the 70s, etc.  SURE, they have advertising in them, but it's 40 years OLD !  I for one enjoy seeing the old ads and depending on the mag's subject matter it gives me some insight into the prices of items advertised.

ANYWAY, a set of encylopedias would be no problem...the weight issue is of course the main thing. I suggest putting it in one way via usps and then when it comes time to actually ship it (if eBay) you will have the choice at shipping time to look at the prices for sending it any usps method possible. Could be a couple of flat rate boxes would be cheaper than media mail (that or parcel post).