Replacement burnisher stone

Agate or hematite replacement stone for burnishers

This stone are only for burnishers "Matthieu Coulanges". For all other brands, contact me

Why choose a stone burnisher ?

The stone burnishers are commonly used in jewelery for polishing metal, copper or other. Industrially, stone are more difficult to manufacture, this probably explains that it is rarely used for modern prints tools. My stone burnishers are positioned on the niche of small burnishers for details work. They are hold like a pen, or horizontally. Stones does not rust, and they are much harder than the materials used to make metal burnishers. They are maintenance free.

What kind of stone ?

Stones have a natural grain that gives them specific polishing / scraping characteristics. These features are commonly used for sharpening tools, but much less for burnishers. I propose two types of stone, agate and hematite. On request I can make burnisher in a synthetic stone. Agate and hematite are harder than the metals commonly used for burnisher, very resistant under the pressure of burnishing, on the other hand they are brittle to shocks. To give an idea of the hardness, on the Mohs scale, the diamond has a hardness of 10, the agate 7, the hematite about 6. A knife blade about 5, a nail about 2.

Agate and hematite are traditionally used in jewelry and other trades involving polishing, from the needles of luxury watches to aircraft engines. The agate polishes perfectly, and has an extremely fine natural grain, which makes it possible to perfectly polish metals. The hematite is also polished perfectly, but observed under a microscope a very slightly grained surface is observed. On a metal plate, it gives the feeling of slipping and being softer than agate. It seems that in printing, one can get better whites with hematite than agate.

On request I propose a synthetic stone which has a very slight abrasive. This abrasive characteristic makes burnishing much more effective, but does not polish perfectly. This stone gives a very light grip on the plate, and allows a better control of the gesture. It is a very good complement of agate, especially in a mezzotint. It is between the scraper and the burnisher.

What shape of stone ?

The shape will depend on the use. I currently propose 5 shapes for each stone. In general, it is necessary to use the burnishers with a moderate pressure (beginning of process) to very light (to complete the polishing). The smaller the area of contact between the stone and the plate, the less pressure must be used. Too much pressure will mark the metal with the shape of the stone. With rounded burnishers, the contact surface is always quite small, which is why I propose truncated burnishers, or with flat surfaces. The flat parts increase the contact area with the plate and help to polish properly, without mark and without wave. If this is your first agate burnisher, I recommend the "Flattened & curved" stone, in addition you can also take the "superfine cone, 1mm truncated", or the "superfine cone, flat end". If you wish a double burnisher, with the two types of stone, go to this page

From left to right :
- Rounded cone : Classic shape of burnisher, you can use the end or the sides.
- Superfine cone : Only for extremely fine details. The most difficult shape to use. In upright position, use only caressing the plate to not mark the metal.
- Superfine cone, flat end : Allows almost as much finesse as the version without flat end, but the flat end helps polish. Designed to be used vertically.
- Superfine cone, 1mm truncated : A larger contact area (tip diameter about 1-1.5mm) for more gradual and easier burnishing.
- Flattened & curved (agate only for the moment) : Allows a gradual burnishing for gradients in mezzotint, but can also be used with a lot of pressure for dry point corrections etc. (nevertheless always finish the burnishing with less pressure)

Agates	Hematites

Zoom on the shape "Flattened & curved"