The ambitious project that made 210,000 publicly-owned oil, tempera and acrylic paintings available to view online for free has taken another important step forward thanks to winning £125,000 funding.
The Public Catalogue Foundation (PCF) completed its initial task last December, using the BBC's Your Paintings website to display art from 2800 collections. Now the Arts Council award means an Oil Paintings Expert Network (OPEN) can be set up.
Many art dealers are backing the project, and Dr Bendor Grosvenor, a director of Philip Mould & Co, is one.
"It's hard to overstate the significance of what the PCF has achieved in recent months," he said. "Not only has our entire national collection of oil paintings been photographed and made available online for the first time, but now, with OPEN, we have the next essential and logical step in the mission - to fully understand what the national collection contains."
OPEN will be a network of specialist art historians whom regional museums can contact if they need specific expertise.
"Such a body is needed for, thanks to the PCF, we also have a broad understanding of what we don't know about our national collection: of 210,000 oil paintings now on Your Paintings, 30,000 have no artist attribution at all," said Dr Grosvenor.
PCF director Andy Ellis called it "a radical new way of helping collections".
"Many museums that have participated don't necessarily have a fine art focus or are just very small - something like half of the collections taking part had ten or fewer paintings. That gives a sense of why this is necessary," he said.
The funding will cover the set-up and running costs for the first year.
"The focus now is really on putting in place the technology that will allow the collections to make the requests to experts," said Mr Eliis.
Experts may spend only a few hours a year on the project, and while art historians would deal with questions about attribution and execution, other specialists could also contribute.
A steering panel including Dr Grosvenor will help design the process. One trustee - David Ekserdjian, professor of art history at Leicester University and a former editor of Apollo magazine - also used to work for Christie's, who have been supporting the PCF.
Other PCF backers are dealers Abbott and Holder Ltd; Blain Southern; Daniel Katz; Hauser & Wirth; Hazlitt, Gooden & Fox; Jonathan Clark Fine Art; Liss Fine Art; Lisson Gallery; Messum's; Offer Waterman & Co; Paisnel Gallery; Philip Mould & Company; Richard Green Gallery and Simon C. Dickinson.
Mr Ellis said a section of PCF called Art Detective, asking the public for information on paintings, had received about 6000 emails in the past 18 months. "There may be a sitter in a painting in a local museum, a mayor for example from 30-40 years ago with no name mentioned, and someone will know who that might be - that sort of local knowledge is very useful," he added.
They are also starting to look at covering sculpture in public collections, but that will depend on further funding.