Excuse me, I thought there was an exhibition in this gallery. The place is a mess. Look at that broom in the corner. There’s even a dust sheet left on the floor. Where’s the art?

Susan Collis’s work isn’t easy to spot. At a recent show she took part in at the Victoria and Albert Museum, comments such as the above could be heard from some puzzled visitors. However, a few moments spent observing the leaning broom, the paint-spattered table, the grubby dust sheet, should have clarified matters. Those specks of paint were painstakingly inlaid mother-of-pearl and black diamonds; the droplets of grot, minutely embroidered silk. Collis’s work takes time, not just for her, for viewers, too.

On Thursday, a show of her work opens at the Ingleby Gallery, Edinburgh. Ingleby has just taken up a new space on Calton Road, which makes it the biggest commercial art gallery in the UK outside London. You’d expect fanfare. With Collis though, Ingleby has wisely chosen to provide a haven of calm from the festival madness outside.

Once inside, you must slow down, look around, stretch your neck or bend down to peer at things easily missed. The pay-off is a moment of revelation, and delight.

Collis is interested in the hidden processes behind the making and display of art – the hanging, the repainting of the gallery before and after a show, the making-good of the space, the walls, the floor. Long Gone (2007) is a series of what look like turquoise plastic rawlplugs and holes, left in a blank wall after hanging works have been removed. In fact, the rawlplugs are crafted from real turquoise, and the holes are dots of smoky topaz. Rock Bottom Riser (2007), a permanent piece in the floor of Collis’s London gallery, Seventeen, looks like a trail of carelessly dripped paint, but is made of inlaid mother of pearl gemstones. Collis will install a similar floor piece at Ingleby.

In some ways, Collis’s work is a product of her delayed awakening to art. Collis, 52, took a degree in cultural studies and worked in publishing production for ten years. (“Plastics directories. I used to get photos of men standing by their hot stamping machines that they were really, really proud of.”) At this time she met her husband, Peter, an experimental film-maker. He had been to art school and it was immersing herself in his world that turned her on to art.

Speaking at her little Hoxton studio – with Peter tucked away in a corner drawing – she recalls how she started a prefoundation access course at Kensington and Chelsea College. “I just remember thinking this is the most liberating experience! It felt like going back to primary school and being allowed to play.” A foundation at Chelsea College of Art and Design came next, then a BA, and finally a masters at the Royal College of Art. “I was 44; apparently I’m the oldest student who’s ever gone on to be a practising artist.”

Does it bother her that her work has such a strong self-referential, art-centric aspect? “Um, yes. In my defence, I’d say it’s something I can’t really help doing. Having been on the outside, to me it’s really interesting. When I did my cultural studies degree, I was really interested in Brecht’s plays. If somebody was suddenly supposed to be dead they’d go to the front and put white powder on their face, and it made everything really clunky.” It’s this drawing attention to the making, to the crafting of what the spectator is looking at, that appeals to her.

The trompe l’oeil aspect of Collis’s work came as something of a surprise. “The first piece I made in this vein was at the Royal College, I made the boiler suit there [100% Cotton, a boiler suit hanging on a nail with paint marks stitched on]. I was going to do it with paint but I ended up using stitch and when you work on something like that so intensely, it just doesn’t look like [trompe l’oeil] to you. When I put it up for the summer show everyone was going, ‘What, what are we talking about here?’ That really surprised me. Watching people, watching the penny drop, it does seem to be dependent on people’s eyesight, but it’s at that sort of intimate distance that you suddenly realise you are not looking at what you thought you were looking at. I became quite seduced by that.”

It is quite seductive for the viewer, too. Perhaps it’s something to do with the sense of revelation, but there’s a complicity which opens up between the viewer and the artist that is very appealing. It’s the kind of work you like to show to other people, and watch their response as realisation dawns. There’s also a certain choreography that becomes apparent, as each viewer cranes their neck or bends their knees to get a closer look at each piece. It’s like a little initiation dance; you do it, then you have joined the club.

Talk turns to Collis’s status as a “female artist” and she looks a little weary. “I don’t know how I feel about that,” she says. “I’m moving into doing more architectural detritus, the batons you get left over after a wall has been clad, and I’ve been working on big industrial brooms. ”

These new objects don’t carry the same connotations that a domestic broom or a dinky stepladder might.

“I think there is something about the scale of the objects I was using before, especially the stepladders, because they are quite cute objects; it just slightly irritates me that things can end up looking a bit more cute than I wanted them to.

“A lot of people who talk about the work think I’m interested in that idea of women’s work. It’s funny, because at Seventeen, they have got a male cleaner and I was watching him push the broom around. I’m just interested in the little acts that go unnoticed, I don’t see them as being gender-specific at all.”

So don’t be disconcerted by the empty space when you wander in to Ingleby off Edinburgh’s heaving streets this August. Take a deep breath, look around you, and be delighted.

Susan Collis, Ingleby Gallery, Calton Road, Edinburgh (www.inglebygallery.com 0131-556 4441), from Thur

Editor's choice

• The 100 Best Films of the Decade
• 70 facts you didn't know about Marvel
• The 50 Biggest Movies Of 2010