Matte Proof Lincoln cents can be authenticated by examining die characteristics common to all examples of the coin struck from the same die. In addition to the smooth and wider edges with steeper drop off, matte surface appearance, and sharper
embossment due to higher pressures being applied by the press these die characteristics are well known. While time and toning of the coin will wear down or mask die scratches originally on the die
that manifest as raised elements on the coin, some or part of these die characteristics will remain and permit authentication of the coin. The dies themselves will also wear down as they are used and
will produce different characteristics on the minted coins depending on the state of the die.
The linked pages below include close up photos of those identified die characteristics as described in Kevin Flynn's marvelous book
that I could also identify at least in part on the coins in the collection. I could not identify them all and there are also some duplications with obverse and reverse characteristics which are reportedly
due to different die sets which I'm not sure I understand correctly but this is what I found. All but the 1910 coin in the collection are PCGS or NGC authenticated. The 1910 was a raw coin I won at auction from a well known dealer.