Gold-Leaf-23.5kt Dukaten-Orange Patent-Book, 25 Sheets of Gold Leaf Size - 3-3/8" x 3-x3/8" Patent Leaf 18 Gram Weight 23.5K Dukaten or Ducat or Orange gold is a very early Karat weight. This came from melting down the Austrian "Dukat" coin that was a very popular form of currency in early Europe. Gold-Leaf-23.5kt Dukaten-Orange is surface leaf therefore it is Loose Leaf.  Each Book of 25 sheets has a coverage area of 1.98sq ft. (without consideration for waste or overlap) This is Patent leaf also known as Transfer Leaf, each leaf is mounted to special tissue paper.  Gold-Leaf-23.5kt Dukaten-Orange Patent-Book