I've got a long rectangular path and two dashed stroked paths running down each side creating a strip of film.
(viz. film emuslion=rectangle, perf=dashed stroke). I want the dashed stroke to knockout the rectangle punching holes in the object. I've tried all pathfinder options and none work.
If you've actually used a stroke and then 'dashed' it by entering pts for the gap and dash, then make sure you first (select the dashed line) check under the Object and then Flatten Transparency. Make sure the "Convert All Strokes to Outlines" is checked. Then, Expand those lines. What you're doing is creating individual boxes which then will work with the pathfinder options.