Then the steel is heated to welding temperature and covered with anhydrous borax.

Next the steel is struck by a power hammer to eject the borax, allowing the two steels to weld together.

Depending on what heat source the smith wants to use there are three types of heat sources I have used: propane, coal and charcoal. I now use a self-built propane forge, as it gives a constant heat and heating it is relatively inexpensive. The most important thing is to have a constant temperature which is clean. I run my propane forge slightly gas rich to stop oxydization. It runs at around 1400-1450ºC.

Depending on how the smith likes to work, the steel is either split by a splitter and folded. This method creates a thicker layer in the middle or alternatively the bar is drawn out to the appropriate length and cut into pieces.

The oxide is ground off with a grinder.

Then it is restacked black/white/black/white and then rewelded using the same method. When the smith gets to an appropriate number of lines, like starting with 6, drawn out into 4 pieces and welded again, that creates 24 layers. That drawn out, cut again in four layers will create 96 layers.

When this is drawn out again into 3, and then welded it will create 288 layers. Some smiths say they have created layers of 3000. Unfortunately with this amount of layers, I would say from experience, all you would have left is a low-carbon steel.

Remember that high-carbon steels, when heated to high temperatures loose carbon content by decarbonization. So speed is of essence. The faster you can heat the steel and weld it, the better it will be for the blade.

Then the steels can be manipulated through cutting, twisting, chopping, double-folding, you name it, you can do it (if you can weld it) to create whatever pattern you want to have. The sky is the limit.

There are many legends and fairy tales about what pattern welded steels can do. I generally stay with the metallurgy and would say that as long as there is enough high-carbon in the mix of the two steels (like 1:1545 at 1% carbon and L6 with .5% carbon). When you combine these two steels, as a mass you should have 1.5% carbon in the block. After folding and decarbonization, I would hope to have around 1% to .8% carbon evenly dispersed throughout the block. This would be enough to create a cutting edge of Rockwell 58 to 60.

1:1545 and L6 have a close AC1 temperature. So they harden relatively at the same time and have similar tempering temperatures. When you have combined 1:1545 and L6 after the folding process what you are left with is neither 1:1545 nor L6. It is a hybrid steel of the two. So, if you use a steel like 1:2767 which has a 4% nickel content and a 1.3% carbon content but which is an air hardening steel (hardening temperature 950°C) with 1:1545 (hardening temperature around 800°C). Yes, you get the black/white effect. However, if you use this to create a pattern and then harden and temper, the hardening temperature of the 1:2767 is much higher and you will destroy the grain structure of the 1:1545. So you will end up with a hard/soft or hard/not so hard cutting edge. Keep in mind that 1:2767 and 1:1545 will create a hybrid anyway. In this case, when I use these steels to create a pattern, I make a sandwich (see also thered handled knife), the core being of a 1:1545 or L6 which I then harden and temper to that steel, allowing the outer two skins to do their own thing. This allows me to get a very good grain size, which makes a good blade.

There are other types of pattern-welding called loafing or mosaic damascus. Another type is Anglo-Saxon or macavenian patterns. This my favorite area of play.