The negative is placed on the glass with its emulsion side up, and the paper is placed on the negative with its emulsion side down. Then a spring-held back is locked into place. The print is exposed by a light held several inches above the frame for five to 15 seconds. The length of time required depends on the density of the negative and the type and grade of paper used. One or two test prints are usually made to determine the correct exposure for the final print.
Contact printers are also available that contain their own light source.
The exposed print is then processed in the developer solution. Contact paper is usually left in the solution for about one minute. The tray is gently rocked or the print held by a corner and moved back and forth. The print is then placed in a tray containing a stop bath, where it is agitated continuously for five or ten seconds. Finally, the print is dried.