In the threading diagram each column is a card and the rows are the holes in the cards. The color of the square represents the color of the thread through that hole and the slanted line is the desired twist of the cord created by that card. The slanted lines represent the direction of the twist of warp thread in the cord as the cards are turned forward. All the holes of a card must be threaded the same direction. Looking from the top of the card a S threading will go through the hole slanted \ and Z threading will go through the hole slanted /. Please note that the slant of the thread through the hole is the opposite of the slant of the twist of the cord when the cards are turned forward. Turning the card backward will twine the warp thread in the cord the opposite direction. I have seen other ways to describe the treading of the cards, but feel the S/Z method is best. The weaver can be left or right handed, sit on either side of the loom or thread from either end of the loom and the result will be correct. The cards can be made of anything. The smaller the thread and tighter the weave the thinner you want the card to be. Besides cards you can buy, playing cards, leather, sheet metal, thin wood, lacquered cloth or cardboard, and shell can be used.