|The Cuticle Database Project aims to promote the understanding and identification of living and fossil plants using the first large, unrestricted visual library of leaf cuticle available on the Internet. Most specimens so far deposited are illustrated with two images, showing the upper (left) and lower (right) cuticle surfaces. The images are accompanied by metadata, including herbarium voucher data that can be queried through either the simple or advanced search options. Original nomenclature from the voucher specimen has been retained (the name on the image file is the originally submitted name). However, updated family and genus designations are maintained in separate data fields (when available). Families and genera names are updated according to APG terminology, using occasional automated queries to the Kew Genus + APG Family Lookup. Non-angiosperm families and genera names follow the Kew Herbarium Catalogue. Species authors assigned according to the Missouri Botanical Garden Missouri Botanical Garden. To fix obvious typographical errors, species epithets were verified in three online databases (Tropicos, The International Plant Names Index, and The Plant List). Not all errors in the originally submitted name are resolvable, and these are noted with a (?) at the end of the name. No attempt was made to resolve synonymies, as these are not universally accepted by the scientific community, and we felt that this was a task best left to the individual researcher. The Cuticle Database Project is a collaborative effort between researchers at Northwestern University, The Field Museum, the Florida Museum of Natural History, and Pennsylvania State University. The original image library was created using the large cuticle reference collection built over several decades by Dr. David Dilcher. Both the originally sampled specimens and the prepared cuticle slides are archived at the University of Florida's Museum of Natural History. Dr. Dilcher's collection was imaged as a part of this Cuticle Database Project by University of Florida students Lens Louis and Nakia Wilson, under the supervision of Terry Lott and Hongshan Wang. at the Florida Museum of Natural History. Undergraduate student Colin Carney of Northwestern University (now a graduate student at Penn State) was responsible for developing protocols that increased image processing speeds. Students Jenny Kissell (Penn State) and Catherine Snyder (Florida Museum) helped tremendously when checking for taxonomic errors. Development of the Cuticle Database was managed by Dr. Richard Barclay (Northwestern University, now a Peter Buck Postdoctoral Fellow at the Smithsonian Institution) in collaboration with Dr. Peter Wilf (Pennsylvania State University). Principal funding for the project came from a David and Lucile Packard Fellowship to Dr. Wilf, with supplemental funding from NSF grant DEB-0919071; early support came from NSF grant EAR0643290 to Dr. Brad Sageman (Northwestern) and Dr. Jennifer McElwain (University College Dublin). The Field Museum in Chicago hosted a preliminary version of the database, with technical support from Peter Lowther. The Cuticle Database is now hosted on the servers of the Environmental Computing Facility of the Earth and Environmental Systems Institute of Pennsylvania State University, directed by John Miley. Database design and development were conducted by Dr. Alex Sokoloff, with graphic design by Jessica Leon-Guerrero, and web design implementation by Chris Thurman. Multiple research grants supported David Dilcher to prepare modern plant cuticle (chronological): Yale University, Cullman-University fellowship, Eaton-Hooker fellowship, NSF postdoctoral fellowship, Sigma Xi grant-in-aid, NSF GB 5166 X, Indiana University grants 10-241-68 and 10-441-68, NSF GB 12803, 1972-1973 John Simon Guggenheim fellowship, NSF GB 32289, NSF BMS 75-02268, NSF DEB 75-02268A1, NSF DEB 77-04846, NSF DEB 79-10720, NSF DEB 79-06837, NSF BSR 83-00476, NSF BSR 86-16657, NSF 9631371, NSF BSR 88-00-900, Becker-Dilcher paleobotany fund, University of Florida foundation. We would also like to thank Katherine Dilcher and the many undergraduate and graduate students who worked in the laboratory of David Dilcher laboratory at Indiana University, for the uncountable number of hours spent preparing thousands of slides of cuticle.