Ever wondered if someone could really put on someone else's face like they do in Mission:Impossible? Or why Madame Tussauds waxworks don't always look as much like their human counterparts as you expect them to? Neill Gorton, BAFTA-award-winning CEO of Millennium FX, has been working with prosthetics for over 20 years, and had the answers to these questions and more when I met him at his workshop.

Entering the workshop of Millennium FX is a bit like being in the film Men In Black: you find yourself surrounded by the wildest looking aliens, many of them from the company's amazing work on Doctor Who. Despite a frighteningly impressive awards cabinet, Neill is a very nice easygoing guy who was happy to explain the finer points of his craft.

First thing I saw on arrival was a collection of body parts. Millennium FX have done a lot of work for medical simulations, and they have several new born baby models which they hire out. These have joints inside their arms and legs, which mean they are totally realistic in the way they react to movement.

They also have a range of pregnant bellies in various states of caesarean section operation. Our skin 'floats' on us, loosely 'associated' with us by fatty material. Plastic surgery to repair faces from burns etc. involves cutting the skin, detaching the fatty link material, and then restoring it in a new location. The prosthetics can simulate each stage in the process, with different models showing layers of skin and muscle when the cut appears to have been made.

Preparing prosthetics for film action where they are cut or show a wound is a process that involves careful preparation. The model makers are experienced in allowing for re-shooting several times, but Neill does have to warn film makers against an actor's tendency to 'pull off' the piece of prosthetic they are supposed to be moving.

The last 20 years has seen the development of new chemicals for prosthetics of increasing variety and flexibility. Some are still inappropriate for use against real actor's skin and can only be used for models. What you can never experience in films is how realistic these things are to the touch!

The skin of the masks is particularly realistic. For animated heads they also add the hairs individually. I was admiring the detail in the mouth of a werewolf-like face when it opened its jaws! Neill had operated it with a lever out of sight, which I hadn't noticed. When I recovered from the shock (!) we continued with the tour of the workshop.

Millennium FX also worked on Catherine Tate's masks for her 'Nan' and 'Derek Faye' characters, and while I was there I saw a face mask created for David Tennant. These days the wearer's face can be digitally scanned to a high degree of accuracy, so the mask created will be an extremely good fit. For a small alien in an episode of the Sarah Jane series they even scanned the actor's whole body (in their underwear!) to build a suit that would fit naturally.

So, if the wearer of the purpose built mask puts on or loses weight, will their specially crafted mask still fit? Yes. The materials have enough 'give' in them that they can allow for most normal changes.

Apparently 3-dimensional 'printers' are now available at a cost of a few thousand pounds, that will 'build' up and even colour in a model from digital scanning. Miniature recreations of heads have been created in this way (eat your heart out Gerry Anderson!). They can also create 3D versions of creatures only dreamt up in computer graphics.

Musing at the accuracy of this technique I asked Neill why Madame Tussauds didn't, in my opinion, always look like their intended subject. The answer is that they don't use the new high tech techniques, preferring to stay with their traditional wax sculpture processes, and as a result they can only ever be as good as the talents of the particular sculptor.

So what about Mission:Impossible - could I put on a mask and look like someone else? Alas, no. Whatever you do with a mask it won't alter the dimensions and spacing of your eyes and nose. You can disguise yourself, absolutely, but you can't change the basic dimensions of your face. Apparently the police are even looking into all this as a way of confirming identity.

So what about the implications for 'face transplant' operations that were being excitedly discussed a while back? Well, it turns out that even if you take the skin from another face to put onto someone's burnt face, the reconstruction will reflect their skull shape and so become uniquely theirs.

Millennium FX work on everything from international productions down to the small-scale use of demonstration items. So for all your prosthetic needs, and more pics of super aliens and faces, check out their web site at www.millenniumfx.co.uk.

Parsley the Lion's own website is gardenrecords.com and he can be contacted via parsley@gardenrecords.com.