Die Trial. An early strike during setup of a coin or medal press in which die alignment, pressure and rotation may not yet be perfect. A die trial usually lacks a depth of relief before the pressure is fully brought up (it looks like a worn coin) and is discarded before satisfactory setting of the press for a production run. Die trials are sometimes struck in lead or other soft metal blanks instead of production blanks. Such soft metal die trials are similar to lead proofs (except they exhibit both sides, lead proofs are usually one- sided). Lead die trials usually show an imperfect die alignment and an extended flash (being struck in soft material without a restraining collar).

Die trials of coins. Every time a press is setup a number of trial impressions are taken, adjustments are made until the pressman is satisfied that all is in perfect order. The die trials of coins are usually destroyed – but these have reached circulation and the hands of collectors. To eliminate die trials of current coins, the U.S. Mint at Philadelphia has at times employed nonsense dies, then replaced these with normal working dies before the start of a production run. The Royal Canadian mint has made small production runs of an experimental pieces or test coins; testing innovative bimetal compositions.

Off metal blanks. Blanks of base metal have also been used for precious metal coins and medals; thus bronze blanks have been widely used to test the dies intended for gold coins (rarely silver coins). While these pieces are highly prized by collectors, they have been called a number of different terms in addition to trial strikes: die trial strikes or trial pieces, and since they are off metal, they are called OMC for off metal composition.