Sharpie Mini Fine Marker 4 Colour Pack - around £4
Available on-line and in many high street stores - shop around for deals

Sharpie pens are a brand of permanent markers that can be used to write on almost any surface (including glass, metal photos and foils), and will dry almost instantly.

The Sharpie Mini Fun Permanent Marker Pens, 4 Pack is filled with pens that are about half the size of 'normal' sharpies. They are approximately 9.5 cm long from base to the lid tip. The pack of pens that I bought had a cardboard backing, and a see through plastic square bubble attaching them to the board, they were hanging in the stationary isle of a supermarket. The pack that I bought had four 'funky' coloured pens they are, green, orange, turquoise and bright pink. I would say the line drawn with them is around 1 to 2 mm wide (it did get wider as the pen became more 'worn down').

Each marker came with a lid that has a clip on it (to hold it to say a pocket front) and also a removable cap to the lid itself. This small cap has in it a metal ring so the pen could be attached to a keyring or lanyard. This would probably be a choking hazard for small children - but I have to say that of all the pens in the world not to let a child near permanent markers have to be the top of the list. The nib itself looks much like a felt tip, and is wider at the bottom (where it attaches to the pen). Be careful though as this ink does not wash out...

My mini sharpies have lasted an absolute age (two years so far - but I don't use them everyday). In my experience they have written on everything that I have tried them on (that has a smooth surface - so I've never tried them on a brick for instance - but just the thought sets my teeth on edge). I tend to keep one knocking about in the kitchen and they will write on cling film, tin foil and freezer bags with ease. I often use them before throwing bits in the freezer, and the writing will stay nice and clear, and it has never run if the item if it has gotten wet after the ink has dried. (They don't like to write on surfaces that have already got damp, but I have found that to be the case with most pens especially if they have a fibre tip). I realise they have many other uses, and have to say the one draw back for me is that if used on 'normal' paper they do kind of bleed or show through on the other side - but this happens with with all permanent markers I have ever used.

They are nice and compact - which was useful when I was asked to write down people's times after a race as the pen did hang nicely around my neck on a ribbon - however the little cap that the metal lop is attached to does have a habit of coming off if tugged too often or too hard...

An absolute bargain and I would recommend them to anyone.