Package or large envelope?

[gretschwhtfalcon]

I often sell items in padded envelopes picked up at the PO. I offer free shipping on everything. Should these be listed as "large envelope" or "package"?  I notice that there is a few dollars difference when calculating (first class) postage. Also, the amount doesn't seem to change (when selecting large envelope) when choosing different zip codes. Most of the time I don't even think about it and simply select 'package'. Which is the better to use? Is package basically always a box or other rigid container? I suppose as long as the shipping weight and cost is accurate, I'd just as soon save a few dollars by selecting large envelope. Sometimes these wind up being as much as 3/4 inch thick though so didn't know if that still qualifies as an 'envelope'. I tend to think of an envelope as the typical flat letter or larger size. 

[nobody*s_perfect]

USPS has strict, specific definitions for each of the 3 types of First Class mail: letters, flats (AKA Large envelopes) and packages. Each piece can fall into only one category; the categories do not overlap.

Postage cost for flats is based entirely on weight; as you've seen, it is not priced by Zone.

To be mailed as a flat, the piece must be literally flat (which USPS defines as a variation in thickness not more than 1/4 inch). It also must be flexible and no more than 3/4 inch thick.  It's unlikely that your items in a padded envelope meet all of these criteria. So they are packages.

USPS avoids the use of the term "envelope" because an envelope could fall into any of the 3 types of First Class mail, depending on weight, dimensions (including thickness), flexibility etc.

[bigdeals.etc]

My Stamps.com software allows two package types when shipping First Class... "Large Envelope/Flat" or "Package/Thick Envelope."

I don't know if this answers your question but "Large Envelope/Flat" is for flat pieces and DO NOT contain tracking numbers but is cheaper. "Package/Thick Envelope" is for parcels thicker than 1/4 inch (I think) and does contain tracking. If you value Seller Protection, always choose the latter.

[nobody*s_perfect]

"Package/thick envelope" must be used if your piece is more than 3/4 inch thick.  But it also must be used if the piece doesn't meet any of the other criteria for flats, such as flexibility and even thickness.  It's not just a matter of choosing whether you're willing to pay more to get tracking; each piece is either a flat or a package, it can't be both.

[bigdeals.etc]

Ah, thanks. I knew the limit was something fourths. 🙂

[nobody*s_perfect]

You might have been remembering the thickness limit for letters, which is 1/4 inch