Proof Sets: Sealed or not?

Veep

A friend of mine claims that 1964 proof sets were shipped by the mint un-sealed and that those claiming to be selling sealed sets are mistaken. Is this true?

19Lyds

It's an open debate.

tahoe98

...unsealed?

19Lyds

My understanding is that the Mint Sets were shipped unsealed but they would "self seal" (due to the gummed envelopes) in some long term storage locations.
Proof sets, on the other hand, were all sealed prior to shipping.

I've seen unsealed and sealed Mint Sets but have never seen an unsealed proof set so my leaning is toward all proof sets being sealed.

Some original shipping container mint sets that I've opened have been sealed but since this was due to storage, they pop open quite easily. Caution should always be exercised when paying premiums for "sealed" mint sets and "sealed" proof sets. A sealed proof set should never look brand new since those envelopes are readily available online.

For mint sets, my advice is to buy only USPS Stamped and Sealed Registered Mail Shipping containers.