Contrary to popular belief, cable is FAR more difficult to work with and forge weld then straight laminates.... just giving you a heads up.

  Ok... to your question, The pattern in cable comes from the decarb that occurs between each and every wire when forge welded. 

  The important part with cable, is the size of each individual wire within each "lay". 

  Example:  Let's say the individual wires in a cable are .030" in diameter, depending on how good or how poor the welding technique.... you could get just a couple thousandths of decarb per wire, or if the techniques is poor, possibly .005-.-010" decarb per wire.   Now think about this....IF each individual wire in the cable is .030 diameter, and you have poor welding technique that lands you in that .010" decarb, ya gotta keep in mind that the decarb occurs from ALL "sides" of each individual wire.  In other words you could end up with near total decarb per wire.    You'd have a nice etched patter (as far as cable goes), but the etch would look very "muddy", and the performance would be terrible. 😉  

  TIP: How good, or how poor a blade made from cable performs, is a direct result of how large each individual wire is, and how good the welding technique of the Bladesmith.... although I don't use cable anymore, I've had massive experience with it..... and can tell you that the larger the individual wire, AND the better the welding technique, the better performing the end blade will be.   Towards the end of my time using cable, I got my hands on a "drag line" cable, that was 3" in overall diameter, with individuals wires that measured .120" diameter ( that's just shy of 1/8" for every individual wire in the cable)  Although I had to break it down into individual lays to be able to handle it, is was flat out the best performing cable blade I'd ever produced. 

Another couple of things to know about cable is that it typically has a lot of gease imbedded in it. This must be removed before attempting to weld. I have always soaked it in a jar of laquer thinner for a day or so before taking it apart. What I mean by that is most cable is formed with several smaller cables wound into ropes. Then these ropes are twisted together into a fat cable. A common formation is seven ropes, six wound around a central core rope. This central core might also have a plastic sheath around it. That must be removed as well. Take some time and investigate this cable you have to determine how it is put together before you weld the ends off (MIG or stick) and try to forge weld the thing together.

Pay close attention to what Ed laid out. I have always used the cable bars as an outer jacket around a 1095 core bar. That gives you a knife with a known cutting edge and a high chance of creating a useful tool rather than just a cool looking knife.

Thanks guys, perfect explanations!  I like the sanmai idea too!  makes for a good blade that could have an interesting pattern.