Pin registration is a method of precisely aligning negatives to the paper (or other print media). It is used by alt process enthusiasts for aligning color separation negatives for multi-color prints (gum bichromate), or to make multiple exposures of the same negative to increase contrast (platinum/palladium).
My pin registration hardware design began as an exoensive solid brass alignment strip with brass pins and a modified office punch set to match the spacing of the registration pins.
I started working on the pin register project over a year ago with the help of Christopher James who has been using a prototype of this frame in his Alternative Processes workshops. Even though testing went fairly well, keeping the punch spacing fixed was a problem. Now a new design eliminates this problem and the need for a clumsy office punch altogether.