Medallion Wafers. Colour the best and most transparent glue or gelatine with Brasil wood, tumeric, Prussian blue, lap green, or other colour. Fill up the hol-part of a seal with gum water, mixed with a powder, such as white-lead, red-lead, chrome yellow, lampblack, etc. Leave the flat part of the seal clear; then pour as much of the melted coloured glue on the seal will lie upon it; Let it dry by a gentle heat. When used, wet the paper to which the water is to be applied, and place the wafer upon it.