In Tate Britain, visitor assistants have been told to be on the look out for toddlers and small children approaching the gallery where artist Karla Black has just installed her sculpture, At Fault. Pink, blue, yellow and green powder is spread over the floor, extending from a central piece that looks like a huge boulder made of coloured rock. The colours and textures make me want to touch it, roll on it, eat it. I know that this is not allowed but children do not, and they love Karla Black's work.
"I've had a big bum print on a work at Inverleith House in Edinburgh because a little kid just ran in and sat down. They really like it but it doesn't really work for them because they want to touch it", says Black.
"I feel really sorry for children. My work is really difficult for them because they want to dive right in and they're restrained and then they get upset. I've had a fair bit of damage done to my work by children. There's no way that they can resist it".
And who can blame them, when bundles of soft blue and sugar pink like candyfloss hang from the ceiling? There are ribbons and shiny yellow cellophane, and pink and white plaster that looks like slices of cake. Looking at Black's work makes me remember childhood birthdays, or a perfectly wrapped gift, and sweets. I experience a childlike sense of pleasure and joy, which is so complete that it feels as though my brain has switched off.
"That's what sculpture can do, it can be a pure engulfment and absorption in the material world, when you're not even aware of yourself, when you have no self consciousness, and you're not being watched and you're just purely absorbed in the material world. That is the best possible kind of escape – when you are fully connected to yourself.
"I think about art as a place to behave, as an escape, not just for me but for the people looking at it," says Black.
Her work is not without a serious and cerebral side but there is nothing grim or depressing about it. It is impressive enough for her to have been nominated for the Turner Prize this year. She did not win but that does not bother her.
"I don't think the Turner Prize has changed things. I suppose more people are aware of my work from it, but they're not people I know. The amount of people who went through the gallery was extraordinary, and it was a good exhibition opportunity, which is all I am ever bothered about," she says.
Black is Scottish. She lives and works in Glasgow, and studied at the Glasgow School of Art. Her work may appear messy: piles of powder, scrunched-up paper, and abstract mounds of colour but there is perfectionism within what appears to be chaos, which makes it compelling. The colours are perfect soft shades. It has taken her weeks, months, and years to get them right.
"When I started using colour I did think that if you're going to use colour you have to be really deliberate about it. It does things to people and what it will do is different, depending on what sort of colour you use. I can't use colour indiscriminately. It's too important for that.
"There's a pink that I cannot stand, that I absolutely hate. It's a sort of cerise pink, that's disgusting. I can only go in a tiny little bit of the spectrum, especially in pink. There's a really specific, really pale baby pink, which is what I like," she says.
It does annoy her, however, when her colour palette is labelled as feminine. "It's a bit daft. I don't get annoyed so much as disappointed because they can't go any further than that in their brain. People have all these connotations about pink being for a girl, or colours being girls' colours, which they're obviously not. Loads of male artists make pink work, like Franz West."
Black's work does not always use pink, or blue, or any colour at all. A new work, going on show in Glasgow's Gallery of Modern Art on Friday will be made from 17 tonnes of sawdust. It will be around 24 metres long, and 10 metres wide, and the colours are natural: wood shavings from pine, yew, maple and teak. Above it will hang a giant cellophane sculpture, marked with metallic brown, gold and copper, which correspond to the ornate ceiling and pillars of the room in the museum.
"I do get worried that it won't be any good. I don't really know what it will look like, that's the pressure. I try to do something good but doing it in public means there is much more at stake. It's more of a gamble, a much bigger risk. I don't know whether I've made a good sculpture until it's finished. If you make it in the studio then you know it's good before it goes out," she says.
When Black first began showing her work, she held exhibitions but then had to destroy the work afterwards. Such large and fragile objects were difficult to store, and she had no choice but to throw them away. Now she dismantles work but then re-creates it elsewhere. At Fault was first showed at last year's Venice Biennale, before being re-created in Tate Britain.
"Sometimes it's impossible to make something exactly the same. It's nearly the same. You can see how different and how the same the work in the Tate is from when it was in Venice. It has a lot more powder, which is to do with how it works in the room. I change it to make it where it is now," she says.
She sells work to collectors and museums but she is ever the perfectionist, and the work arrives with detailed instructions of how it is to be assembled and displayed – not pushed against the wall, no plinths, no vitrines. Collectors must send her an annual photograph so that she is able to see what state it is in. She does not let go. Neither is she willing to surrender her work to time, if she can help it.
"Aesthetics are so important to me and the work is not about decay. It is about preserving this really perfect moment," she says.
She is working with conservators who will help her to discover how her work will look in five or a hundred years' time, and how the colours will change.
"I would like my work to remain perfect. The thing that haunts me is the state of Eva Hesse's work. They're absolutely disgusting now, and she never made it like that. She used latex, which was so white and so thin, and now it's brown. No one knows what she would think of it now. Some of it is OK but some of it is in a terrible state," says Black.
It really bothers her that her beautiful work might become old and ugly one day.
Karla Black, Gallery of Modern Art, Glasgow (0141 287 3050) 20 April to 24 June; 'At Fault' is at Tate Britain, London SW1 (20 7887 8888) to 2 January