Scottish actor James Cosmo has had a long and varied career over the past 40 years, appearing in such movies as Braveheart, The Lion, the Witch and the Wardrobe, Trainspotting and Troy. He talks to Matt McAllister about his role in Sky’s adaptation of The Colour of Magic, in which he plays Galder Weatherwax, the incumbent Archchancellor of the Unseen University.

Have you been impressed by the set design on The Colour of Magic?

Just the depth of the office of the Arch-Chancellor…It’s lovely, they’ve done such thoughtful things with stories built around objects that are there. It’s really nice that the art department have done lots of stuff with backstory that will never be told but it’s there, it works. It’s a bit like Blade Runner. If you look at the sets of Blade Runner, almost every scene you can look at and you can see a story behind it. And that’s part of the designer’s work, you know?

Which must be useful for you as an actor…

If you’re developed in that atmosphere, it’s a huge help, yeah. Which is why I think working in front of green screen is horrendous because there is nothing there…

Is it generally true that stage actors don’t mind working with green screen because they’re used to working with nothing there, whereas it’s different for film actors?

My profession, apart from a couple of things, has always been on the screen. I mean, the stage has been enjoyable but it’s not been [a major part of career]. But yeah, I would say that’s actually true.

How have you found working with Tim Curry?

He’s a terrific guy, great fun to work with, a very funny man – very dry...He’s an absolute pussycat. He can certainly put it on, but he’s a pro.

Do you think that Vadim Jean had quite a feeling for the material having worked on The Hogfather?

Terry Pratchett couldn’t have chosen a better guy. Vadim was a fan to begin with for many years. And CGI has caught up so that it’s financially viable to do this now, whereas it wasn’t before. So I think this is absolutely the ideal time to do it.

Has it made you want to read the books?

Yeah. But I prefer to be in it than read it.

Were there any new challenges in this production for you?

Just the perennial challenge of walking and talking at the same time! But no, not really. After 40 odd years most challenges have been overcome by now.

What’s the most surreal moment you’ve had in your career?

Standing in Budapest looking over a huge pair of bosoms in a dress that I was wearing, wondering how women with those size bosoms ever saw their feet! It was a film with Matt LeBlanc and Eddie Izzard called All the Queen’s Men and it was a fairly awful movie. It was a German comedy, what can I say? We were all dressed up as women. Eddie adored it, you couldn’t get him out of the make-up suit. Matt looked surprisingly attractive I have to say – being away from my family for a long time! And because I had these huge bosoms they had to fit me with a huge arse! So I had to wear a false bottom, these false bosoms and I had to wear a floral dress each day…It was soul destroying! So playing a professor is absolutely nothing!

How has Pinewood changed since you were here at the beginning of your career?

It’s really interesting…I was looking around while we were filming and there were three generations of actors. There was a very old actor we had, still working. Then there were guys of my age and then younger guys, all sitting in their chairs. It was like a generational thing, you know? I find it really comforting – guys coming into the business and maturing and ageing…It was lovely you know?