Hidden fore-edge painting (as opposed to standard fore-edge painting) was developed in the 17th century as a novelty technique for book decoration. The beauty of this technique lies in the ‘trick’, in that the painting is hidden or secret unless you know to look. As the book stands on the shelf, and as you’d hold it normally, the painting is undetectable and usually looks like a gilded or marbled fore-edge. However, when the book pages are splayed by bending the text block, the hidden fore-edge painting is revealed. Sometimes, this content was relevant to the text, and other times it was simply an interesting or attractive scene. Typically, these paintings were landscapes, battles, religious scenes or figures, or heraldry. Occasionally, even erotic images were hidden in this way.