What does the US Mint mean by "Impression" 1 1

[usmedalman]

As you can see by my user name and the fact that this is my very first post, I know very little about coins. I have been collecting US military medals for decades and recently began a study of the US Mint's involvement in the production of early US military medals. In going through the US Mint's order book for 1920 I have run across a term that I have not seen before, and after searching a few numismatic sites I came up empty. So I thought I would tap into the vast numismatic knowledge available here.

The term "impression." appears frequently in the order book, usually in conjunction with military collar insignia struck for the US Army. But then I stumbled upon these two entries,

Order #9524 Entered Sept. 15, 1920
12 impressions of the Miniature Victory medal in lead.

Order #9525
1 impression of the Miniature Victory medal in 8K gold.

And on the same page of the record is another entry,

Order #9527 Entered Sept. 23, 1920
3 gold Miniature Victory medals.

It seems obvious that the term "impression" must mean something other than medal. Since collar insignia are one-sided, does the term imply that just one side of the medal was struck, maybe for display?

I would any comments on this.

[RWB]

When a die is pressed into metal, moist cardboard, etc. it is called an "impression." Same as "strike" in coin usage.

[Sandon]

   In other words, the number of "impressions" means the number of pieces made in the indicated metal.  If they were coins instead of medals, we would refer to the number of pieces "struck", rather than "impressed", by the dies.

[Henri Charriere]

Possibly analogous to dental impressions taken of each jaw in a special clay-like substance preparatory to making dentures.

(I do not, of course, speak from personal, first-hand experience.)  

[usmedalman]

Thanks to those who replied, especially RWB.