Pattern welded steel can be made in an infinite variety of patterns. Some of these have names given by the maker, some don't.
Random damascus has the look of tree rings, long linear rows of dark and light steel. Twist and ladder patterns are made by twisting the forged billet in different ways. Ed Caffrey's 'spiders n snakes' damascus pattern is formed by making specific angled cuts through the completed billet (the completed welded stack of metal).
Some makers specialize in producing damascus for other knife makers (Devin Thomas, Robert Eggerling, etc) and are known for particular patterns. Birds eye damascus made by Herb Derr is made by drilling holes in a completed random billet, and filling them with jelly rolled tubes of steel and reforging the billet. Mosaic damascus is another type made by particle mettalurgy techniques. Some makers have developed their skills to the point that they can write their name in the blade material (e.g. Al Dippold) or create elaborate pictoral scenes (e.g.
Ron Newton).
The 'Montana Bunch', comprised of folks like Rick Dunkerly, Shane Taylor, and others hold all night hammer-ins experimenting with making different 'damascus' patterns. I have seen a few knives made in 'mystery' patterns which are very unlikely to be reproduced again by anyone because the maker forgot to make notes about the things he did to the billet in the making of the steel.
There are many many different patterns that are used in the making of blade steel. That is one of the things that is so fascinating about damascus blades, each is just a little bit different. Some patterns are relatively easy to make, some are very very difficult and time consuming. Some patterns are achieved at the expense of large amounts of steel to make a small amount of finished material.
Have a look at
Ed Caffrey's and
Ron Newton's web sites to see some beautiful pattern welded steel varieties.
This thread on damascus steel is a good read. Search the custom and general forums for Damascus steel for a large number of good threads discussing the making, use, and types of pattern welded steel.
The variety is basically limited only by the imagination, creativity, and Mistakes of the maker.
I could go on for hours, but that probably answers your question and will hopefully make you more interested in learning about 'damascus', or more properly, pattern welded steels.
Paracelsus
[This message has been edited by Paracelsus (edited 01-17-2001).]