Because patterned Damascus can be forged from mild steel, many of the fake blades that exist today were formed from cheap pieces of flat-rolled steel with a fake pattern-welded onto them. These pieces of flat-rolled steel are easy to spot. Any steel can be forged into a stick, but real Damascus will have a patterned texture as well. To see if your piece is the real deal, you can look at it under a microscope. What you want to look for are bands that are lighter or darker than others in the pattern; the bands will alternate between being wider and narrower than their neighbors. The welds sometimes show smudge marks, but sometimes you can see two or three bands in a row following the pattern of the blade. One way to tell that your blade is straight from the forge is to look at it on a flat surface so that its shape is more or less uniform. The high carbon steel will tend to lay in one area of the billet, while the low carbon steel will tend to lay in another area. A real piece will have a pretty even distribution and "live" surfaces. Any blade will have variations in the way the pattern is laid out, but that just indicates individual style. There shouldn't be any major pattern discontinuities between two areas of high carbon steel or two areas of low carbon steel. Keep an eye out for "floaters" in the patterned area of your knife. These are little bits of low carbon steel in a sea of high carbon steel. They are usually black or very dark compared to their neighbors, and they are floating freely like icebergs in a sea of steel. This is always a sign of some type of low-temperature work. If your blade has floaters in it, keep looking! Another thing to look for is evidence of grind marks on the surface. Some forgers will intentionally grind off one side of the patterned area to create an interesting color differential. Others will grind through the pattern to create a whittled or "lumpy" look. Either way, if you see elongated scratches or abrasions in the pattern, keep looking!