I was asked (and posted in an earlier thread) to describe some of the differences in available synthetic brush types and what to look for in each and what were some of the differences between synthetics and naturals. Here is that quick synopsis. Since there have been some new players and some major changes since that thread was posted, the information has been updated and placed in this thread. Synthetic brushes capture / retain water differently than naturals and those qualities allow them to dry much faster. They do not behave like naturals and should be classed in their own group based on feel and performance, just as Badgers, Boars, and Horse hairs all display and have different characteristics in feel and performance. Good synthetics can start at an inexpensive price point and work up depending upon generation of the fiber the size, the handle, etc. Now their are three major points of discussion. The first is the generational grouping of synthetics. This is important because all of these are on the market today and it can lead to confusion. The generations are really based on the development of the fibers and are the changes significant to group them together for comparison. The second concerns the strengths of synthetics as compared to naturals. The third concerns the weaknesses of synthetics as compared to naturals. The Generations of Synthetics: The first generation knots were made of base Nylon fibers (used in early toothbrushes and mono filament fishing line) which was developed in the late 1930s and early 1940s. These were / are white and are like lathering with a bundle of fishing line or a super boar that never gets soft. They are still available in cheap disposable travel brushes and in the Omega White Syntex. I do not recommend these unless your face needs a very good scrubbing. The second generation knots came out in the early 2000s. Taken from the cosmetic industry, these nylon brushes were flagged more at the tips to allow a softer feeling and some were dyed to approximate a more natural look. The early versions of the MenU, Body Shop, and Parker synthetics used this fiber type. The were prone to doughnut holes when getting moist and were not strong performers but some people enjoyed them more as an alternative to naturals than on performance. These behaved more like a cross between horse and boar hair brushes. These improved and more usable fibers helped to begin the quest for better versions of synthetics. The third generation knots came out in the later half of the 2000s. Taken from the cosmetic industry, these nylon brushes were flagged and / or tapered more at the tips to allow a softer feeling and some were dyed to approximate a more natural look and feel. Closer to badger but not exactly like badger. The fibers tended to be thinner so that more hairs could be packed in a bundle for a denser brush. The performance of brushes using this version improved dramatically. The Jack Black, Three Band TGN, Omega Synthetic (not the white nylon), Kent Silvertex, and a variety of other makers use this class of fiber to create higher performing brushes. There are some major (at one time all natural) brush makers that have also introduced their first offerings using Generation 3 fibers more than likely either made by a knot maker that specializes in synthetic knots or are making their own using the Generation 3 fibers to establish a presence in the marketplace. A half step up from the third generation (Generation 3.5) came out when Muhle took the Generation 3 fibers and began to crimp and adjust the lengths of the fibers to create a brush that looks and behaves more like natural hairs. This is what is known as the Version 1 of the Silvertip Fibre. This is a much higher performing brush than brushes using Generation 3 fibers. This came out in the early 2010 time frame. The generation 3 and 3.5 fiber class really allowed synthetic brushes to become more popular and accepted in the traditional shaving community. The fourth generation knots came out in the early 2010 - 2012 time frame. Brushes that so far have been released using this class of fibers are three which are, the H.I.S. brush, the Version 2 of the Muhle Silvertip Fibre, and the Frank Shaving Pur-Tech. These fibers are flagged and / or tapered even more at the ends to increase softness and to improve lather application. The fibers are also more flexible than what is found the third generation knots that can allow the fibers to be shorter yet retain excellent backbone. These have a reputation for being softer at the tip than other synthetics and are the "state of the art" fiber at the moment. The question that stands now is when will a new generation type of synthetic fiber become available given that there are more players entering the market both in terms of making their own knots or using knots supplied by larger producers. The strengths of synthetics are as follows: The synthetic fiber is solid versus naturals which have very small pits and pockets when viewed up close. The naturals are also based on protein. So the solid fiber will not absorb water and product while the naturals will. So a synthetic will create more lather with less product because it will not absorb or hold water. For this same reason, the synthetic fiber will dry faster than the natural product and will resist issues with product calcification, etc. You will use less soap and cream and still get the same amount of lather with a synthetic over a natural. The synthetic fiber is stronger than the natural fiber. For example, when I want to do strong circular motions with a brush, I will grab a synthetic over a natural because I can make hard circular motions without worrying about fiber damage. In fact, if taken care of properly and under equal conditions a synthetic will outlast a natural in the long term because the protein fibers will break down over time quicker than the synthetic fibers. I have unboxed synthetic fiber brushes made in the 1950s that looked and felted like the day they were made, whereas equivalent natural brushes the knots had deteriorated even under NOS situations (color fade). Consistency is greater in a synthetic. If you have two brushes with the same knot, handle and loft, there is almost no variance whereas the naturals have variance even with the same hair grade. Synthetics can handle higher temperature (not extremely hot or boiling) water than naturals which will damage the hairs. The weaknesses of synthetics are as follows: Feel at the tip. Good synthetics (Gen 3) are soft and great synthetics are really soft at the tip (Gen 4), but they are not the same feeling as a natural badger. Water retention. The strength becomes a weakness because the synthetic does not retain water, you must modify your lather development to accommodate the lack of retained water that can be used with a natural. Once you learn the proper technique of gently shaking the brush to remove excess water and generating a proto-lather, you simply add a slight bit of water and then produce the lather. It should lather well when you develop that technique. Heat retention. Synthetics will lose heat faster than naturals, so if you like warm lather a natural may be more your preference. Backbone variation. Synthetics have one backbone setting whereas you can variate the backbone in a natural brush by the amount of time you soak the brush in water. Shorter soak, more backbone, longer soak less backbone. Soaking is not needed with a synthetic since it cannot absorb water. Cache and tradition. Naturals have a higher cache than synthetics and have a long tradition of use. Conclusion: Personally, I use synthetics as often as I do naturals and enjoy them as much based on the strengths they bring to the table. I hope this provides some greater detail into synthetics.