The Victorians used a technique called ‘nature printing’ to reproduce the details of leaves, plants, and other flat things like lace. This relies on pressing the specimen into soft metal (lead) to make an impression like a footprint of the item, and then making an electrotype of that impression in a harder metal, such as copper. The prints are produced with the intaglio method, in which the ink sits in the impressed areas and is forced into contact with the paper by the high pressure of the rolling press. This contrasts with relief printing, in which ink sits on top of raised lines. Here we have printed directly from the soft lead plate into which the leaf was impressed; the fine details on this lead plate will only last for a couple of impressions, though, before becoming smoothed down by the pressure as it goes through the press.
Learn more about nature printing.
Some examples of nature printing in Bodleian Libraries collections:
Thomas Moore, The ferns of Great Britain and Ireland (1855) [i.e. 1856]