Basic Flintknapping Techniques & Tips

Introduction

Flintknapping is fun, and it is not really very complicated. It is not, however, as simple as it looks. There are a variety of ways a beginner can go about learning the skills required to create stone points and tools. In this article, we lay out the core principles and rules that should be the basis of any flintknappers tool kit of skills. Though any of these concepts can independently be understood relatively easily, only considerable application in practice can ensure that he/she will successfully meld the different techniques into a skill set that will result in useful and beautiful stone tools.

Do not be frustrated if you don’t create a masterpiece on your first or even twentieth try. Your skills and understanding should evolve with every failed and successful attempt. Learn from every broken core and step fracture and determine how you would do it differently next time. When you run out of practice stone, you can either source if from your local natural surroundings as the Native Americans did, or purchase it from a flint knapping stone supplier.

Safety

Knapping is not really a very dangerous activity, IF proper precautions are taken. Small cuts are, however, a constant threat, and a few things can be done to minimize injury.

A SERIOUS CAUTION- The flakes you remove are sharp and effective cutting tools, and if you continue long in the hobby you WILL see your own blood. Luckily, the sharp and sterile flakes generally deliver a painless cut and tend to heal nicely. With reasonable care, flintknapping is safe, relaxing and extremely rewarding.

PROTECTIVE EYE-WARE IS REQUIRED FOR THIS ACTIVITY. Although very few flakes will fly off toward the eyes when the proper form is used, flakes can bounce off the pad, and even pressure flaking can launch an occasional flake toward the face. PROTECTIVE GLOVES can also help ensure that hands are free of cuts when flintknapping.

*Always chip with adequate ventilation. Although most knapping materials break into flakes that fall harmlessly to the floor, some are so brittle that their chipping dust will float around the room. Obsidian and materials from highly mineralized areas are the highest risk stones. An exhaust or circulation fan that will maintain a flow of air to carry off the dust, or better still, knapping outdoors, will help keep the hobby as safe as possible.

*Keep your knee pad clean of chips and flakes. If there are loose flakes on the pad the likelihood is greater that you will press against one and force it into your finger or the back of the hand. A flick of the pad after each successful pressure or percussion flake will keep things as safe as possible and will make for better flaking.

*When pressure flaking, try to keep the core firmly secured to the knee pad. There may be some times when you want to elevate one end or the other of the core to push a particularly long flake off, but even these moves should be made with the core held or propped firmly on the pad. If the pressure flaker ever slips up over the core when you are running a long pressure flake, a nasty cut can follow when the hand that holds the flaker strikes the working edge of the core. For this reason, it is always best to apply pressure in an inward and downward (toward the pad) direction. This way, if the flaker slips off, the hand pushes into the knee and not into the core.

*Do not attempt to work on a wet pad or with a wet core or tools.

*Keep your pressure flaker sharp; a sharp flaker takes less force to use than one with a severely rounded tip. A tip about as sharp as a broken off pencil is good for most detail work, and a slightly duller point can be used for larger flakes. The best way to sharpen a pressure flaker is to pound it into a point with a hammer or hammer-stone. This will harden the copper as it sharpens the point and will make the pressure flaker last longer.

*When billet flaking, never strike the core from the back with the billet traveling toward the face. Even the lightest tap from this direction will spray the knapper with flakes. WEAR PROTECTIVE EYEWARE!

Universal Platforming and Targeting Method

We begin our instruction with the process of creating platforms that make targeted flake removal possible. Whether you choose to start your learning using the billet in percussion flaking techniques or the flaker in pressure flaking techniques, a knapper will most definitely need to understand the correct way to prepare the point of impact for pressure, also known as a ‘platform’.

1) Locate the ridge or high spot to be removed by noticing which spot sticks up highest above the core center-line (center plane). Place the core on your knee so that this spot is in the ‘up’ position.

2) Follow a flake scar junction (ridge) from the high spot to the nearest suitable edge. This location will be the right spot for the platform that will remove the ridge and targeted area.

3) “Munch” or “nibble” the edge of the preform at this spot to bevel the edge of the preform. Use pressure in a downward direction, that is, delivered at a right angle to the core center plane. This will serve to bevel the edge and to bring the edge of the preform (up) onto the same side of the core center-line as the flake to be removed. The proper amount of beveling, as well as how much above the centerline the platform needs to be, should be evident with some practice. A good rule of thumb is to try not to bevel up more than ¾ of the way between the center plane axis and the top of the flake you want to remove. After this is accomplished, grind the edge lightly with an abrasive stone. This will strengthen the edge, so it does not crush when pressure or impact is applied. The ground area is the finished platform ready for either pressure flaking or a percussion strike with a billet.

4) Turn the core over after nibbling so that the flake scar junction to be removed is touching the leather pad.

5) -A- Percussion Flaking – If the platform is set up correctly, the angle and speed in which the domed billet head strikes the platform will determine nearly everything about the flake that is removed. Strike the core edge by line of sight, and with medium intensity. Holding the core at the correct angle is essential and will vary slightly with the size and shape of the targeted flake. For more information about optimum striking angles, refer to the Percussion Flaking section.

5) -B - Pressure Flaking - Touch the platform with the tip of the flaker, and firmly but gently seat the tool so it will not slip when pressure is applied. Firmly hold the flake down with the free hand and increase the pressure on the flaker in an inward direction. Push in the direction you wish the flake to travel. The amount of inward pressure you use will help determine the distance the flake will travel. While holding your inward pressure, at the last moment, add a little downward pressure to help ‘pull’ the flake away from the core.

Pressure flaking

Percussion flaking utilizes a hammerstone, billet, or baton to strategically knock off flakes of various sizes. Generally, the larger the flake to be removed, the larger the hammerstone or baton (billet) employed. More on percussion flaking later.

After a flake or core has been worked down to the desired thickness of the finished piece, pressure flaking techniques are used to trim and sharpen the point or tool. For small arrow points made of good material or precut stone slabs, all or most of the work may be done with pressure flaking techniques. A properly chosen flake is a good first project for the beginner that wants to understand the pressure flaking process.

To pressure flake, the core or flake must be held firmly with one hand and the pressure applied with the other. Right handed persons must hold the flaking tool with their right hand, and lefties must do the reverse. It is most comfortable to chip on the knee opposite the hand that holds the flaker. Beginners
should master pressure flaking on the knee with a firm leather pad before attempting other methods.

Before removing a flake, a platform must be prepared to accept the force of the pressure flaker and to target the section to be removed. The importance of platform preparation cannot be overemphasized.

Platforms should be located at the junction of previous flake scars. The ridge formed by this junction is relatively easy to remove. A platform must always be made on the same side of the core center-line as the flake to be removed. Don’t break this rule! Also, the face of the platform should be lightly ground before pressure is applied. This is done so the edge does not crush before the flake comes off.

After the edge is ‘nibbled’ to create the proper form of a platform, seat the tip of the copper tipped pressure flaker on the edge with minimal pressure. If an audible crunching sound is heard, stop, because the edge should be further ground before proceeding. At this point, begin to increase or ‘stack’ pressure on the platform using the handle of the flaker as a fulcrum. Pressure should be applied in a more or less downward direction, isolating the flake scar junction, and shooting the flake to the proper side of the centerline.

If you did everything right, the tip of the platform and a flake ½ to ¾ inch long will peel off and be resting on the pad when you pick up the core to examine for your next platform location. To determine the best location for the next flake, simply look for the spot on the preform that sticks up highest from the core centerline or center plane. Follow a flake scar junction or ridge to the nearest edge and construct another platform.

These are the basic moves. Shaping is a process of nibbling with downward stokes, platform preparation and grinding, and removal of pressure flakes to thin the piece while changing the outline.

Occasionally, a desired flake may be too big to remove by pressure. When the need arises, a platform should be constructed as for pressure removal and a billet should be used to strike off these larger flakes. The piece is then finished by pressure flaking.

It is up to you to choose the right flakes for removal in the right order to bring an arrow point out of any particular core or preform. The thing to remember is that pressure flaking, like all flintknapping is not a random activity, but depends on the consistent application of a few simple laws of physics.

In review, make sure you understand the following.

Remember that nibbling or beveling the edge to make a platform is done with the preform on the knee and with the targeted flake in the up position. To remove the targeted flake by either pressure or percussion, the core is then turned over so that the targeted flake rests against the pad on the knee.

Remember the 5 step universal method for platforming.

Best Materials for the Beginner to Pressure Flake

A beginning flintknapper who is trying to get a feel for the craft should stick with the most knappable materials, and these should be in the form of thin flakes.

Obsidian and slag glasses are remarkably consistent and have always been the pressure flaker’s material of choice. Ranking next after the natural and man-made glasses are the finer grades of natural and heat treated flint, such as the Ohio or Alibates variety, opal, and heated Novaculites and fine Texas flint. Chert can be a good material as well in the finer grades, but heat treatment of Chert is an absolute must for the beginner that wants to use pressure techniques.

After pressure working several small flakes, the beginner will likely be ready to try his/her hand at some light percussion billet work.

Percussion Flaking

The previously outlined pressure flaking technique and 5 step universal method presents the basics of platform anatomy and tells how flakes are pressed off using the pressure method. Percussion flaking uses the same type of platform accompanied by a strike from a billet or hammerstone to thin and shape stone tools or cores.

Spalling, the initial stage in the reduction of blocks, utilizes hammerstones or very large billets to remove giant flakes for later finishing. Spalling requires a few very accurately placed blows, so the beginner should familiarize himself with facture mechanics in general before attempting to break up large blocks of fine expensive knapping stone.

Most of us have seen the cone-shaped fractures that a rock or BB will make when it strikes glass at sufficient velocity. Percussion flaking uses a portion of this cone of force (or Hertzian Cone) to remove stone flakes from a core. Usually, the upper 20% of this cone is employed to remove a flake. Straightness of billet travel, consistency of the core material, and the shape of the platform will to some extent distort the cone, but it is important to understand that the basic geometry of flake removal depends on this simple physical principle.

Grinding of the platform surface and edge are very important in percussion flaking. The edge must accept the shock of impact without crushing. Crushes make the notorious ‘step fractures’ that so often blemish stone tools. Good platform preparation – nibbling and edge grinding, and the proper positioning of the core relative to the line of billet travel are the main controllers of step fractures.

A core laid flat on the knee and struck on the edge from above will show steep edge flaking. Beveling of the edge using this technique is the equivalent of ‘nibbling’ mentioned in our pressure flaking instructions, and it is useful in platform preparation and outline shaping.

Review the 5 step universal method of platform preparation outlined earlier in this text. It is the basic method for targeting used in both pressure and percussion flaking.

There are two important points for the beginning knapper to remember. One is that line of strike should be the same as line of sight. This will cause the billet to travel in a straight line to the core instead of an arcing line. The other is to avoid ‘pulling’ your strike. Smack the core as if you were actually aiming at the leather pad beneath the stone.

To strike a thinning flake that runs across the surface of the core, turn the core over after nibbling, and locate a suitable spot on the face of the steeply beveled nibbled edge.

Grind to strengthen the edge, hold the core firmly down on the knee, and strike the selected platform with enough force to remove a thinning flake. A little practice will reveal the proper angle for the core. The properly executed thinning flake will run across the surface of the core as opposed to the short beveling flakes caused by a more vertical blow.

Holding the core too flat on the knee (at a right angle to the billet travel) will result in short, steep flakes. Holding the core at too steep of an angle will result in step fractures. A given blow will only run a flake so far, and if the core angle directs the flake into the interior of the stone the flake will snap off when it can go no further- leaving a step fracture. It will take a little while to see the proper mix of core angle, billet strike force and platform location, as well as the proper spot on the platform to strike.

Aside from percussion flaking on the knee, one should master freehand percussion flaking. The freehand method requires that the core be held firmly in the hand and the angle changed with the wrist and fingers.

The hand that holds the core can either be rested on the knee or held suspended in midair. Freehand chipping works well on some of the more brittle stones as it helps cushion the shock of impact and guard against end and blade snaps.

Billet size is an important consideration, especially for advanced work. A billet too large for the job is an aggravation. A billet too small for the job makes thinning difficult and is an invitation for end snaps, step and hinge fractures.

The ideal billet end is semi dome shaped. The strike can be made with either the tip of the billet or the inside edge of the dome. Accuracy of the strike is dependent on the sharpness of the striking point, so as the dome flattens from use it is important to resurface it. A rasp or course file is probably the most easily acquired tool for antler billet re-surfacing, copper boppers are usually thrown away and replaced after exposing the lead core, and solid copper billets can be hammered or ground into the desired shape.

Indirect percussion using an antler punch can be employed for notching and fluting, but for the beginner most of the ‘tricks’ are either confusing or at least are the wrong thoughts to seek for rapid advancement. The inexperienced knapper should settle on a particular style of pressure and percussion, use high grade spalled knapping stone, good posture, and the simplest set of rules possible to acquire a basic knowledge of fracture mechanics.

All flintknappers, especially beginners, should remember to TAKE THEIR TIME. Avoid rushing and try to chip in a relatively calm setting. Speed may come with practice but the best knappers do not rush. Platform preparation tends to take longer than actual thinning and shaping, as it should. Just because a platform or prepared edge is the right shape to remove a flake is no reason to strike it – it should be the right shape to remove THE flake that needs to be removed. Proper attention to platforms makes the difference between regular and random flake scars and the flatness of the finished piece.

Some Tips for Knapping Success

It will take a while to develop a feel for manipulating stone through pressure and percussion techniques. There are a few obstacles that can be particularly frustrating, and a little instruction and study can help speed your mastery.

STRATEGY- Use the 5 step universal platforming method, think in terms of your core centerline (center plane), and DO NOT remove flakes that do not need to be removed.

MULTITASKING- In flintknapping, it is important to proceed with shaping and thinning as deliberately as possible, as there are only so many strikes that can be made on a core before it is chipped away. Whenever you can, prepare a platform at the same time you are changing the outline shape in the desired way. In other words, try to accomplish more than one maneuver at each step.

SNAPS- These are probably one of the beginner’s most serious problems. Snaps can be caused by poorly prepared platforms, inaccurate strikes of the billet, or a strike from the end of a thinned blank that breaks the tip far from the strike point. These snaps are associated with percussion flaking, and although they might seem mysterious at first, there are generally very obvious causes that are avoidable. Pressure flakers need not fear these most common snaps but must take precautions against simply breaking the point in half by pressing too hard on a thin flake. The best preventative is to chip on a very firm pad that consists of two or three thicknesses of leather. The pressure flakers’ snap occurs from too much pressure in the middle of a flake that is supported on both ends. You can either minimize the support on one end or minimize the pressure applied to the middle. Holding the preform on edge and using properly abraded platforms (not too strong) will help avoid snaps in pressure flaking.

PLATFORMS- A mastery of the art of platform preparation is the most important facet of good flintknapping. Any conceivable pressure or percussion platform can be constructed in the proper place with just a little effort, and the beginner should consider him/herself as a constructor of platforms BEFORE considering themselves as a striker of thinning flakes.

NEVER TRY TO REMOVE A FLAKE ON ONE SIDE OF THE CERTERPLANE BY STRIKING A PLATFORM ON THE OTHER SIDE OF THE CERTERPLANE, NEVER.

ALWAYS TRY TO LOCATE THINNING FLAKES SO THEY HAVE A FLAKE SCAR JUNCTION (RIDGE) IN THE MIDDLE OF THE FLAKE. THIS WILL KEEP THE FLAKE FROM BREAKING AS IT COMES OFF AND WILL ALLOW IT TO TRAVEL FURTHER.

A common mistake is to skip the abrading step in pressure and percussion flaking. This will usually lead to trouble, but the knapper can get away with it for a strike or two. DO NOT TRY. Abrading strengthens the edge so that it can accept enough force for a GOOD flake to travel. Abrading also roughens the surface so the billet or pressure flaker will seat properly as the flake is being removed. Pressure flakers should be especially aware of seating the flaker before applying the final pressure. About 1/3 of the total pressure should be used to initially seat the tool on the edge. If an audible crunching sound is heard the edge should be further ground. The sound is nature’s way of telling you that the edge is not strong enough to accept the proper force.

Those who have a serious desire to learn to knap or those who simply want to know more about knapping should read “The Art of Flinknapping” by D.C. Waldorf. This well written and illustrated book is a worthy addition to any flintknappers, archaeologists, or collectors bookshelf.

Glossary of Flintknapping Terms

Percussion Techniques- A set of methods using a billet or hammerstone to strike and remove unwanted flakes from a piece of knapping stone. Most commonly used for thinning medium to large flakes. Striking with the billet should be at the proper angle and should impact a platform designed to remove a specific targeted flake.

Pressure Techniques – A set of methods using small points of ‘stacking’ pressure to run delicate fine flakes or nibbled notches. Used for edge finishing and notching of points and other stone tools. Common tools used for pressure flaking include antler tines, nail punches, and copper tipped pressure flakers.

Hard Hammer Techniques – Percussive blows delivered by very dense instruments that do not have any ‘give’. Examples of this technique require the use of hammerstones or modern steel hammers.

Soft Hammer Techniques – Percussive blows delivered by a semi soft domed instrument. This generally allows for a softer impact, allowing the instrument to spread the cone of impact in a slightly larger area than what would normally happen with a harder instrument. Traditionally a blunt antler is used, while progressively more modern knappers utilize copper and other soft metal domed billets for this.

Flake Ridge – The well-defined high points left after striking a flake. These are normally created on both sides of a removed flake. The flake ridge left by one percussive blow can subsequently be used as the backbone of the next flake and so on.

Notch – A ‘nibbled’ gouge, groove, or other modification to a stone tool to increase its usefulness by adding the ability to haft, or attach with binding, to a stick or other medium.

Billet – A percussor, or blunt semi domed baton primarily used in percussion flake removal techniques. Traditionally antler from deer or moose.

Pressure Flaker – Primary tool used in Pressure Flaking techniques. Semi-sharp and small, the flaker gives a much more deliberate concentration of pressure by the action of bearing down on the handle, and ‘stacking’ pressure, after the tip is seated properly on a pre-designed platform.

Abrader- Sandstone or modern equivalent that is used to strengthen an edge so that it will not crush when pressure or percussion is applied. Simply grind in a downward motion to prepare a platform; be sure not to abrade too much or the area will be too blunt to flake properly.

Center plane (centerline) - The one dimensional imaginary plane (axis) that lies at the very center of a stone tool that extends from edge to edge. Imagine slicing the point in half through the edges (the hard way) and this slice will be along the core center plane.

Platform – A targeted area of impact or intense pressure from either a Billet or pressure flaker. Where the platform is placed, and the angle of the platform, determines much about the nature of the flake that is to be removed.

Beveling – Primarily a ‘nibbling’ action performed in the creation of a platform. Proper Beveling will move the platform, or ‘striking point’, above or below the center plane of the piece; this allows the knapper to remove thinning flakes from the piece without affecting the desired core within.

Step Fracture- A negative result of an overly steep angled percussive blow or bad platform preparation. This term is used to describe when a flake terminates ‘in’ the stone, creating a sharp, square ridge at its end point. More often than not, trying to strike in the same point again will just make more step fractures. To fix, try targeting the sharp ridge from a different platform altogether. To avoid, take your time and try not to be too aggressive in your angle of strike and be sure to abrade your platform.

Core- The piece of stone from which flakes will be struck

Preform – A core that begins to approximate the shape of the finished tool.

Biface- A spall that has been worked considerably with semi-consistent thinning flakes removed from both sides.

Spall- A medium to large sized workable piece of knapping stone in its raw form. Created after ‘spalling’ a nodule or block of material into manageable sized pieces.

Cortex- A Natural layer that surrounds a block or nodule of potential knapping material. This outside layer has usually been exposed to the elements and is not optimal for flintknapping. Most cortex's should be removed to expose prime knappable stone.

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