I am one of those rather strange artists,

who paint pictures that people can't see;

it's a discreet painting,

it's only there when you know how to unlock it,

now you see it, now you don't.

My name is Martin Frost,

I am what's known as a fore-edge painter,

so I paint pictures on the edges of books,

but I do it in such a way, that they become invisible,

unless you fan the books up in a particular way

and then you un-fan the book, and it vanishes again;

they're gone, vanished,

because the gold has hidden the image.

It is pretty much a British, if not English art form.

Vanishing fore-edge paintings date back to about 1660.

It really got going back in the 18th century

when it became quite popular.

I was working in illustration,

and I met a fellow, who was a fore-edge painter,

and he showed me what he was doing and I liked that,

I thought, "that looks fun, I could do that."

And that, as I said was over 40 years ago now.

Most of the work I've done has been on antique books.

I'll show you this one:

Now here, we have here a large Shakespeare;

it's 1860 leather-bound, split double,

two different images on one book.

This is a book entitled "Desert Isles."

It was produced in the 1920s.

This is known as a two-way double,

one one way and one the other,

and both of them will be hidden under the gold.

I'm often asked by people, "And how long does this take?"

"How long is that piece of string?"

If you're working on a very small book,

it will take you a few hours,

generally speaking, for a typical book

of about that sort of size, a day-and-a-half, two days;

if you're working on something like a big Bible,

it's not difficult to use a week.

The price reflects the time that goes into it;

the bigger Bibles, the big ones,

ooh, six, £700, something like that.

Ah, yes,

another Harry Potter, let me just open it up.

Gone.

I find these quite satisfying.

As far as I know, I am the only

commercial fore-edge painter working,

and so long as my eyes hang on in there

and my hands, I'll continue,

but if I'm ever asked to describe myself, I say "I'm a dad,"

I'm a grandad and I'm a fore-edge painter,

that works for me.