I know that some people here on the forum don't think that stencil priniting was used in the initial release prints of Oz for the moment the film goes from sepia to color. Two things jump out at me: 1. In the Cutting Continuity script, several scenes were missing because special effects for those scenes were being worked on. The shot of the inside of the door was one of these scenes, indicating that it may have been undergoing some sort of effect, ala stencil printing. 2. The effect is briefly mentioned in The Wizard of Oz: 50th Anniversary Pictorial History. Also, I've heard that when MGM was working on The Women that they used the same stencil technique for the floor show that they used for Oz. The effect looks a lot better and more seamless in the 1999 disc, then on the current one. Hopefully, for the HD release, they can make it look more like the 1999 version.