Long weekend of experimenting with different films, ortho films, xray and duplicating films, graphic arts films in lith, starting with an IR neg and contacting printing it onto the films, then re-contacting those onto others to create positive/negative enantiomers. What appears as mackie lines is the umbra/penumbra of two emulsions separated by the two film bases . . .the duplicating film and the graphic arts film base is quite thick, so the effect is pronounced. (Not to say solarization was not a technique that went untested, I just couldn't get it to worK.) This is a lith print from a final single piece of graphic arts film.