The threepence, with a diameter of 16 millimeters and a weight of just 1.4 grams, was the smallest coin of the Australian pre-decimal (or Commonwealth) series. The small size caused a number of problems in its manufacture. To achieve a well struck result, the intricate dies had to be engraved with extreme care. Attention also needed to be given to regular cleaning of the dies during production. Unfortunately, such care was not always observed. The results are weakly struck coins from poorly engraved dies and loss of detail when the dies became clogged by oil, dirt and other foreign matter.