Stamps (Philately)/postal envelopes
I need some info on uncirculated postal envelopes I have apack of2 cent 2 cent imprinted envelopes small and large 6cent airmail big and small and all sorts of post cards all in mint condition. They are from the 50'-60s Any info would help to put a value on them . Also have more types of envelopes mint condition. Thankyou
Hopefully you are asking about US envelopes. The general price guide is the Scott Specialized Catalog and the specialists use the UPSS catalogs. Much of the material from that time period sells in bulk at less than face. Individual items are priced starting with what is essentially the cost of handling, not a value of a collectible. There are few better items and those tend to varieties of the surcharged envelopes issued in 1958. Except for certain varieties of interest to the specialist, this is true for most envelopes up to the present. Most 6-cent airmail envelopes the same, again with a few very specific exceptions. Postal cards also mostly common with a handling value.
Stamped envelopes and postal cards, mint, still retain postage value. Collectible value, as for any collectible depends on condition and demand and just like postage stamps, a lot of stuff was saved by collectors and investors.
Your local library should have a copy of the Scott Specialized Catalog. When using any catalog assume you have the least valuable variety, not the most valuable, because that is mostly true. If you find something you think is the valuable variety, then seek help.