Obtaining good quality film positives for photo mechanical processes can be difficult. Below are a list of recommended repro houses based in and out of London who have been making positives for years. Be sure to know what line screen you want before you contact them. If in doubt, ask in the print workshop.
Hexio are a specialist repro house based off the Old Kent Road and will produce the best quality imageset film for screen printing, photo lithography, photo etching, polymer and gravure.