The print on demand (POD) system, launched on Monday, means visitors will no longer miss out on the chance to own a copy of their favourite masterpiece. Storage and printing costs had previously meant the gallery could only offer a very limited range of around 60 posters and prints. But using the POD system, which has been trialled for two weeks, visitors can manipulate a touch-screen panel to access 900 of the 2300 paintings in the gallery's collection and then print a highly-accurate copy in minutes.
Claire Gough, head of media for the National Gallery, said that not only can the gallery offer a greater percentage of its collection to the public, but the instant prints are often a more accurate representation of the original work than the traditional prints it carries in its shop.
"Having extremely accurate reproductions is extremely important. We need to have very good reproductions for study, academic journals and for members of the public," she said. Working closely with HP, the gallery's photographic department scanned the collection over a two-year period using a MARC II camera, which captures high-resolution images at 100 megapixels. Consumer cameras typically have a picture resolution of around five megapixels, according to HP.
The data is being held in a digital archive consisting of two Netserver LH3000R servers, more than 4 terabytes of online RAID-configured disk storage and an Ultrium tape storage jukebox. The system also uses four HP workstations, two of which run on Linux and are capable of generating 1,000 print PDF (Portable Document Format) files a day.
Vyomesh Joshi, HP's vice president of imaging and printing, said the project represented the first "baby steps" of digital technology's eventual impact on the art world. "I think it will be just like the music industry. The same revolution will happen with fine art," he said.
Although there were some copyright concerns -- there are no plans to include visiting exhibitions in the scheme -- the gallery's Gough claimed that it shouldn't face the same copyright issues as the music industry, since no one is given access to the original digital files. "In all of this we have to balance the restrictions of copyright with the benefits of widespread distribution to the public," she said.
HP claims that the gallery didn't have to do any customisation of the vendor's large-format printer to achieve the required 4 delta E standard of quality -- also known as JND or Just Noticeable Difference. The HP Designjet 5500 PS printer used in the POD kiosk has a 42-inch capacity and retails for around $10,000 (£6,400).
The rest of the collection is expected to be available by the end of the year, and the gallery is considering allowing Web access to the system eventually.
The National Gallery is working to bring the print-on-demand technology to other British art collections, including the Tate.