MGM invented an interference-free toning process, which was used in films such as "The Wizard of Oz" (1939) and Warner Brothers' "The Sea Hawk" (1940). Many MGM movies of the 1930s carried a sepia-like tone called "Pearl". The Technicolor Corporation continued to experiment with both tinting, toning and colorizing. The last reel of "Portrait of Jennie" (1948) contained both green and amber tints by Technicolor. "Mighty Joe Young" (1949) displayed a further concept of tinting by Technicolor, with various shades of red, orange, and yellow creating a fire-like effect for the last reel. The Cinecolor Corporation also created similar effects, and sepia-toned several films as well as tinted select scenes in chapters of the 1951 Columbia serial "Captain Video". Over the years, general rules of thumb were developed for what color to use in certain scenes. Many of them were obvious, but a few artistic. Specific names were given to tints to specify certain colors. Striking effects could be achieved by both tinting and toning sequences. In order of most common:   The process for tinting was laborious, although simple in principle. Editing was done in rolls based on tint color, with numbered frames of film in between scenes for later assembly. Once these rolls were printed and processed from the negative, they were immersed in aniline dyes, specified to the colors that were listed in the script or continuity. Hardening fixer was not used on the film in order for the dye to be imbibed into the emulsion quicker and with better results. Once the film had dried on large film drums, it would be assembled in correct order and rewound onto reels for shipping. Toning was similar, but instead of aniline dyes, the film was immersed in chemicals to change the silver image into colored salts. Tinting and toning are important factors in film restoration today. They were an integral part of the moviegoing experience and the processes have been duplicated with modern methods for both video and film, based on the specifications of existing documentations on each film.