It's not easy being a spy, as any movie buff will tell you - on the one hand, you need to stay undercover, which means heavy body armour is out of the question, but on the other hand, it's likely that you have a fair few enemies who are out to get you.

Luckily, in the real world, there's a best-of-both solution that won't leave you fending off knives and bullets with nothing more than a good haircut and a witty one-liner.

Whether you're dressed to kill or roughing it in casual clothing, even the most fashion-conscious of spies can now get their hands on bullet-proof vests that won't so much as wrinkle your dress shirt, or cause you to break a sweat at the baccarat table.

Dangerous Denim

Perhaps one of the most subtle forms of ballistic armour you could invest in is a brand-name denim jacket into which a bullet-proof or stab-proof lining has been sewn.

Because denim is a bulky material in its own right, it allows for even quite a strong lining to be added, without obviously changing the way the fabric hangs during wear.

Finished garments can be just a few kilograms in weight, retain almost all of the fabric's original flexibility, and can be comfortable enough to wear for casual use over extended periods of time.

Suited and Booted

For formal occasions, bulky body armour is unlikely to be a possibility, but that doesn't mean you have to go in without any protection at all.

Lightweight stab vests can be worn underneath other clothing, giving a lesser degree of protection against bullets and blades that could still save your life.

You can often add extra protection by inserting ceramic plates into pockets sewn on to these vests - giving you the power to adjust the look and feel of your outfit to suit the occasion.

Braving the Elements

Of course, the real world isn't all casinos and cocktail parties, so for many spies an all-weather armoured overcoat is an ideal way to become a one-man human tank.

Like the denim jackets mentioned above, armoured overcoats can be indistinguishable visibly from their 'ordinary' equivalents, without adding unnecessary weight to your outfit.

But with the ability to resist blades, slashes from broken glass, and even ice pick attacks, they can make for a very valuable garment indeed.

Portable Protection

If the idea of wearing a stab vest at all times is a concern - perhaps because you expect to be patted down at a security checkpoint - then portable protection could be the answer for you.

This includes stab-proofing and bullet-proofing sewn into the lining of a bag, for example, which otherwise looks and functions exactly as a normal bag would do.

In an emergency, pull a side tab and the bag unfolds to provide you with a large, flat piece of body armour, while the handles of the bag become straps with which you can hang it around your neck and shoulders, quickly adding an extra layer of defence to your outfit.