In our last discourse we discussed the virtues and differences between the different types of fibers that can make up a shaving brush. From natural to synthetic, boar bristle to badger hair there are wide differences that can affect feel, appearance, and performance. In this segment we will discuss the benefits of loft and of the knot shape and how they can affect your brush choices.
When we talk about loft in a shaving brush this defines the height that the knot is set into the handle of the shaving brush. Measuring the loft of the brush is done in millimetres and is measured from the top of the handle to the tips of the bristles. The main factor affected by loft is the “backbone” or how stiff the brush feels and sits in the handle. Having a stiffer backbone is easier for loading and lathering shaving soaps. A brush with a 53mm loft and shorter is considered to have a stiffer backbone and a brush with a loft of 54mm and more is considered to have a softer backbone. When loading the soap the bristles are able to press more firmly into the soap and therefore pick up the harder material more easily than a brush with a higher loft and lesser backbone. Conversely a brush with a higher loft will work easier with softer products such as shaving creams. The longer tips from a taller loft also allow for a more pillow like texture with aids in mixing creams and water to form a solid lather.
Knot shape can also affect the lathering ability of your brush and how it performs with different products. There are two main shapes of shaving brush knots: a bulb shape that is very reminiscent of a lightbulb and a fan shape which has a somewhat flattened top. The bulb shape is very effective with soaps and seems to work best with bowl lathering. The rounded shape of the bulb helps to gather the soap from the sides of the bowl and focus the mixing towards the center. Having the soap focused at both the center of the bowl and of the brush creates a very thick and stable shaving cream. A fan shaped knot pulls the soap material from a wide surface area and makes an excellent face lathering brush. The wider area of the fan shape also helps in building lather of softer cream products.
Are these hard and fast rules for shaving brushes? Of course not. Many people use fan brushes for soaps and bulb brushes for creams, however for our purposes those are their ideal uses. The same does not apply for the varying lofts however. A taller loft will work much better for creams and a shorter loft will work better for soaps. We hope this rather extensive look into shaving brushes has given you insight and a good platform into choosing the right brush for your own use.
What’s in a shaving brush? Part 1