I'm assuming you're talking about blade paterns.
Mine are aluminum cutouts in the same profile of my blades.
After I make a blade that I plan on duplicating again, I trace it on paper, then take 1/16 plexaglass, lay it on the paper, and trace the paper drawing. I get me a pattern of the blade complete with the tang curve/angle. I also get a pattern of the handle. After all of this, I grind out the plexaglass and then trnsfer that to 1/8 aluminum plate and stamp my name on it just like a blade.
I keep these hanging by my anvil. As I'm forging, I can refer to the pattern without burning it up.
Lin