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Impressioning - Open the lock and get a working key!

Posted by Chris Dangerfield on

Hello Lock Pickers.

First thing: Impressioning is AMAZING. Don't be put off by what you've heard, or what you think you can do - you CAN do it. And it's absolutely incredible - almost dreamlike!

The Master, Oliver Diederichsen, who literally wrote the book on impressioning, called 'Impressioning'. I've seen him impression an ASEC lock out of the box in under a minute - right in front of my eyes.

TRUST ME: If you read this carefully and get yourself the necessary kit, with a bit of patience, confidence and time, YOU WILL be able to perform this most enigmatic of lock picking techniques. You'll be able to open a lock, with just a blank key, and then have a working key. It still blows my mind.


It's always a huge surprise to me that impressioning isn't more popular. I love it. When I used to teach this wonderful art, after Single Pin Picking I would teach impressioning. And those who were willing to put in the time, and put in the effort, and deal with the failures, the frustrations, the lock-shaped holes in the wall, etc would be exceptionally grateful, because it is without doubt an impressive and extremely useful skill. I know many locksmiths who swear by it - what, open the lock and give the customer a working key? A-M-A-Z-I-N-G!

Oli's book, takes you from the basics right through to impressioning car locks and dimple locks. There's depth charts and it's richly illustrated with colour photographs of all aspects of the impressioning process.

I mean think about it - if you've mastered the art of impressioning, you can approach a lock with a blank key, and with just a couple of specialist tools have a working key in your hand - in about 50 seconds. Yeah - that's right - you'll have a working key in about 50 seconds, you read that right. I mean that's at the top of the game, but is is in reach, 100%.

Those of you who read my blog regularly will know I had the pleasure of meeting the two best impressioners in the world. Oliver Diederichsen who literally wrote the book on Impressioning, called 'Impressioning', and Jos Weyers, who recently added to his list of cup winning performances, impressioning a lock out of the box in under two minutes at an official competition. Part of the pleasure of knowing them was inviting them come over and teach an all day workshop on impressioning. People at that workshop who'd never impressioned a lock were doing it in under ten minutes by the end of that day. It's amazing what seeing it done in under a minute in front of your eyes does for your confidence. It's even more amazing what having world champion impressioners giving you guidance can do for your abilities!

Jos in his trademark kilt, with yet another impressioning trophy for his cabinet. If you lock yourself in a room with a lock and a thousand blanks, you are likely to reap such rewards.

Anyway, I said to Jos "How did you get so good at impressioning?" to which he answered without needing to think, "I locked myself in a room with a lock and a thousand blanks", and if you take nothing else from this blog, take that. If you want this almost supernatural skill, put in the time, the dedication, and the practice - and you can do it. I promise. 

So let's get down to it, what is impressioning? Well, it's possible to 'decode' the biting of a lock (the way the lock is pinned) by wiggling a blank around in the lock. The pins leave small impressions on the top of the key blade. You then gently file these impressions with a specialist file, a round Swiss No4 cut is best, (it leaves a nice smooth surface which allows you to see the next impressions) and repeat the process until, voila! The lock opens. And, unlike all other lock picking techniques, not only is the lock open, but you have a working key, so you can lock it and unlock it as much as you want. Sounds good?

The Impressioning Workshop we organised. That's me in the red T-shirt in the middle, with Oli on my right and Jos on my left. A great day, it really was!

Impressioning is truly and absolutely amazing. Imagine doing it for a customer? They're locked out - they've lost their key, and not only do you get them in, but you can give them a working key. Mind-blowing! It's for me one of the purest arts in lock picking - and YOU can do it.

So - here's a simple check list of how you impression a lock:

  • Put blank key into a key grip
  • Insert blank into lock and turn clockwise
  • Wiggle key up and down
  • Turn anti-clockwise
  • Wiggle key up and down
  • Remove key from lock and identify impressions on top of key blade
  • Gently file where you see the impressions
  • Repeat until lock opens

 And that's it. Below I will go into a bit more detail regarding each aspect of impressioning. But don't let it become too big in your mind. It's actually very simple - which although not the same as easy - it's not rocket science.

Things you will need:

Blank Keys.

Brass blanks are the best for a beginner. The metal is relatively soft and they take both the impressions and the filing nicely. Start with brass and get LOADS of them. 


It makes sense to start with a 5 pin lock. We have the perfect Rim Cylinder in the shop. Let's keep things simple for starters. And a basic lock too, a cheap, generic unbranded lock is ideal. Not so cheap it's all lose and creaky - as that might actually impede your process - but a NEW cheap 5 pin lock is ideal.


Our 5 Pin Rim Cylinder is PERFECT to learn how to Impression.

You could use a 4 pin Master padlock if you really want to make things easy for yourself, and there's nothing wrong with that. But I find such locks actually lend themselves to impressioning, and it might not be good for morale when you successfully impression a 4 pin Master padlock and then not manage a 5 pin 'actual' lock.


Even though I've seen the top boys impression locks with no grips, it's more of a party piece and not recommended. Being able to hold the key tight and with no movement is essential at the beginning. While you can use a set of mole-grips, there's nothing quite like tool made for the job. Mole-grips can lose a bit of accuracy by wiggling themselves, and I've seen someone struggle for weeks before obtaining a Framon and nailing in in a matter of hours. All that was preventing his success was the quality of his grips.

The Framon Key Grip - the king of impressioning grips. It's essential you have a tight, secure, and non-slip grip to get accurate and observable impressions. Leagues ahead of all the other available options.


Actual grips are far superior and will certainly make it easier. There's a few available from online lock pick suppliers, but I've tried them all and nothing comes close to the Framon Key Grip - it's in another class, and will help you no end. It features a quick release feature which is great and grips the key at two points, avoiding any wobble whatsoever. Key wobble caused by inadequate grips are the bane of impressioning and are to be avoided.


 You'll hear or read all sorts of things about preparing your key, but basically take any file and get a nice flat surface on the top of your blank. You're taking about half a millimeter from the top, and then make it smooth - with the right file. To file the impressions you need a very high quality Round Swiss No4 File. Glardon Vallorbe make the best ones. "No4" refers to the coarseness of the cut, and No4 is the best cut for impressioning. It will remove metal as required and will leave the surface you filed smooth enough to receive the following impression, as well as allow it to stand out. The impressions are tiny, almost like a fleck of slightly darker metal, so the smoothness of the filed surface is essential, so get a Glardon Vallorbe No4 Swiss Round File.

Swiss Cut No4 Glardon Vallorbe Round File. There is simply no better file for impressioning. Even in this photo you can see it's as smooth as silk. The perfect balance between being course enough to remove metal, and smooth enough to leave the filing surface just right to receive the next impressions.


A vice is essential. Ideally a dedicated lock picking vice as traditional vices tend to 'spit' out locks or they certainly move about a bit. Rubber toothed vices slowly 'eject' the lock as you're wiggling your key. The complete opposite of what you need. And steel toothed files tend to grip one small part of the lock which again, cause the lock to move - the lock moving is the LAST thing you want. Dedicated lock picking vices are perfect for the job and are good value too.

Lock Picker Vice MK2 - not only perfect for holding locks for impressioning, but designed for all manner of lock picking practice. The lock doesn't wiggle lose, in fact, there's almost no perceptible movement at all - giving you exactly what you need and perfectly mimicking the feel of a lock in a door.


Our Dedicated MK2 Lock Pickers Vice is ideal. It fixes to your table or work surface exceptionally tightly and - being made for lock picking - holds the lock tight. In fact, it perfectly gimmicks a lock in a door which is really the perfect way to learn - as you're actually learning the skill based on locks in situ. It's a doddle to set up and use and I cannot recommend it enough. You CANNOT practice or learn impressioning without a vice, so make sure you get one.


Magnification and Illumination.

This is utterly personal. I've seen people use pocket microscopes, which you can get from ebay, I wouldn't advise going more than x60 or you'll struggle to find the impressions. Some people use a simple x5 handheld magnifier, others use table mounted illuminated magnifiers. Some like ultra violet, and of course, some people use none at all. In fact, I saw Oli and Jos both impression locks in front of my eyes in under a minute with no illumination or magnification at all.

So if this is something you want to try, see what you have laying around the house and take it from there. Not essential, but some people like to use some sort of magnification, and others some kind of illumination. On that note, make sure you are well lit from above. The impressions are tiny, so if you're not using any additional illumination, be sure to practice in a well lit environment.


A lump of Blu-Tac about the size of a walnut is a must have. You stick this on your work table and once you've taken your first impressions, stick the key, top of blade up in the Blu-Tac. that way it's kept in an upright position and perfect for you to inspect, whether you're using a magnifier or not - you can also file the key in the Blu-Tak as it has a little bit of 'give' which helps you not be too heavy handed filing the impressions.


Sounds a bit silly I know, but I've been on a job without a lump of Blu-Tac and not only did it make things tricky, it was almost impossible, and I had to do with a bit of chewing gum, that luckily I had getting flavourless in my mouth all the time. I keep mine (Blu-Tac) in one of the two-part plastic egg type things you get toys in from vending machines. But anything that will keep it clean will do. 





While definitely not essential, I feel like it would be unfair for me not to mention a micrometer, since you will occasionally see people using them - however, you will not see the likes of Jos and Oli using them in competitions. Some people like to use a Micrometer to measure how deep you need to file to go one depth down, since ideally you would be filing exactly one depth down each time. The problem being, a worthwhile micrometer that can accurately measure one depth down will cost a fair amount of money, over a £150. Interestingly, the depths of most common locks are in Oli's book 'Impressioning', and you can also find them online. So if you really want to get a micrometer to be able to measure one depth down for impressioning, I suggest you pay out well. But personally I don't think they're worth it. It's not only cheaper but makes you a better craftsman to develop the skill of knowing how far to file, and to learn that less is more, and more importantly to learn that you can file too little, but file too much and you're screwed. 

And that's it!

So now let's look at technique

Clamp the blank key in the key grip, and tighten the grip. Put the lock in the vice and then insert the key into the lock. Turn the lock clockwise until it won't go any further and wiggle the key up and down. Then turn the key all the way anti-clockwise, wiggle up and down - a couple of times.

Remove the key from the lock and observe the top of the blank. You will see the tiny, tiny impressions. If you've opted for illumination and/or magnification, now's the time for that. If you get out (soon to be in the shop) pocket microscope - now's when you sue that. But like I said, none are essential, so you should be able to identify these with the naked eye in good light. It often helps to tilt the key to get different angles to identify the impressions. But don't look for huge dents, you're looking for tiny scratches really, but they are there!

The impressions appear because when you turn the lock a pin 'binds' - much like most lock picking the 'binding pin principle' comes into use. You don't need to worry too much about the mechanics of this, just think by turning the lock, one pin is trapped between the plug and the housing (stopping the lock turning and essentially stopping it turning fully and locking it). When you turn it anti-clockwise if you're lucky - and more often than not, a different pin will bind - because locks are so badly made - it's the same manufacturing 'faults' that allow us to do most lock picking. So by doing the clockwise and anti-clockwise before a wiggle up and down, you might be lucky and get a couple of different impressions. Sometimes you'll be even luckier and the lock will bind two pins, either side. So don't be surprised if you get more than one impression, or more than two - just be happy!

Now take your Swiss No4 Round file and without putting too much downward pressure, file back and forth a couple of times, so four filing motions in general. Enough to remove the previous impression, and then some - like half a millimeter. This process is actually 'cutting' the key. You're now doing the work that makes the key work. Once you've filed where you saw all the impressions. It;s time to put the key back in the lock and start again.

In time you'll get more used to how deep to file each time. This is something you can only learn with practice. When you watch Jos, Oli and the like they seem to know exactly how much to file to take the key down 1 depth, which is exactly what you want to do - but for now, I would say four draws of the file is enough.

Once you've taken the second round of impressions, you might notice one or more isn't leaving impressions. As soon as this happens you know you've filed enough from that particular part of the key. So concentrate on the rest.

It's quite common to end up with just one impression left, and when you've filed that one, and re-inserted the key and turned it - the lock opens. And a feeling of magic washes over you. You have just opened a locked lock with a blank key, and now you have a working key for that lock. What a skill to have!

There are other techniques like 'rocking' and 'tapping' to get the impressions - and thought time and practice you'll learn what works for you, and what works for different locks and different blanks. But for now - let's continue to keep it simple.

If you're not managing to locate any impressions, then you're doing something wrong. Don't fret, mistakes are what teach us the most. Just adjust your technique slightly and try again until you can see them.

Final thoughts....

Like I said - impressioning is simple - but not easy. But like all such things you'll only get better by practicing and having faith you're learning, even if it doesn't feel like it. Like all lock picking it can be frustrating - but frustration is the enemy of lock picking whatever technique you're using. You tense up, you start rushing things, you hold your tools to tight and all manner of small and subtle changes in your approach will only further the frustration. If you feel this happening. Put the tools down, go outside and focus on things in the distance to give your eyes a rest, have a cup of tea, sit down and then go back once you have relaxed again.


Framon Key Grip

Real 5 Pin Lock

Round Swiss No4 Impressioning File

Lock Pickers Vice

Oli's Book 'Impressioning'


PLEASE PLEASE PLEASE give this technique a go - it really is like magic when done properly, and will add the most amazing and useful skill to your ever growing repertoire.

Best Wishes

Chris Dangerfield.


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