Julian Opie is best known for his ultra-modern portraits with thick black lines and very little detail. So it may surprise museum visitors to see he is a keen collector of grand 17th and 18th century paintings packed full of frilly and intricate fussiness.
The secret passions of Opie are explored in a fascinating exhibition opening on Wednesday at the Holburne Museum in Bath in which the artist displays examples of his own work from the past 20 years with works from his private collection. That collection includes portraits by Sir Peter Lely, Joshua Reynolds and George Romney, and ancient sculpture from Egypt and Rome.
It is Opie's first show in a UK museum for 10 years and the artist said he thought long and hard about whether to do it. "I was anxious about how it could be read and what it could mean. I have seen examples of, say, a contemporary work next to a Vermeer and it's just, 'No, it doesn't really help either.' I hope it will be read generously, rather than 'that lot's better than that lot', which you could end up suffering from."
The Holburne's director, Xa Sturgis, said the theme was a natural fit for his museum, built as it is around an individual's collection. He said he was delighted by how the show looked.
"What I like is that I've never seen anything like it. I hope that is a good thing. It is slightly provocative; it provokes thought and looking, and that is always key with exhibitions."
Opie has divided the gallery space in half – his works on one side, his collection on the other.
It looks and feels different to what we are used to with old master portraits hung on white walls with natural light streaming through.
Opie hopes visitors will make connections, perhaps go around and go back to different works. Yes, they are very different but perhaps they are also similar.
"With old masters there is a slight tendency to go, 'Wow, look at that amazing craft,' and it seems to be outside anybody's imagination quite how the flowers are painted. But actually it was a fairly standardised system as to how to do cloth, how to do flesh and so on. People would have learned it in workshops."
Opie has always used the latest technology so it is perhaps no surprise to see works from 2012 where he has explored 3D printing.
Two larger-than-life busts sit on plinths created using a 3D printer – hand-painted because the technology does not yet allow colour.
Opie said he had not hand-painted for a long time but was helped by a 2,000 year old Egyptian funerary mask from the late Ptolemaic period that is in his collection.
"I often run out of nerve. I think, 'I can't do this', and my hand is shaking and I think I need my glasses," he said. "The idea of what I'm doing … it makes me nervous." So it helped to look at his mask and think some bloke in Egypt on a Wednesday afternoon sat down and did a whole load of them. "If he can do it then I can do it."
Some visitors will be able to spot more direct connections. The blue curtains in a portrait of an unknown woman by Cornelius Johnson – a court painter to Charles I before Van Dyck – inspired the blue curtains in a 2008 Opie work, Maria Teresa with sequinned dress. Opie said he often used the poses of sitters in old masters as templates for his own works.
Many of his collected works are on display in his east London converted warehouse studio. "I find myself feeding off them as I'm working. You never know what you need or will find, so I do learn a lot."
There are many wonderful and striking works in Opie's collection, not least a bust of the 18th-century composer Christoph Gluck from the studio of Jean-Antoine Houdin in which you can see the terrible scarring effects of having had smallpox.
Opie was originally meant to fill just the one room but admitted getting slightly carried away, hence the LED sculpture of a peeing boy and an enamel-on- glass naked lady in the Holburne's gardens. Both are already attracting interest for photographs.
Opie said the painting that got him started as a collector was an oval portrait from the studio of Godfrey Kneller. "It just jumped out to me as being connected, useful and very alive so I bought it."
He also is a keen collector of Manga and Japanese prints but he does admit some art blind spots, chiefly the 19th century. "The sentimentality, self-consciousness and romanticism is like a wall; it blocks me out completely."
• Julian Opie: Collected works is at the Holburne Museum in Bath, from 21 May until 14 September. From there it goes to the Bowes Museum in Barnard Castle, County Durham.