In the drawing of the rear view of the Graflex Series B in , I have used colors to identify the parts of the Graflex back. Blue outlines parts in the rotating section of the back. The main element is a pressed metal structure that engages the metal frame that attaches to the wooden part of the camera. This pressed metal structure rotates on the camera frame. The center of this structure is cut out to form the image frame aperature and the area around the aperature is covered with felt which acts as a light trap. To either side, on the long dimension, are two wooden strips that have the same thickness as the inside depth of the pressed frame. These are shown in brown in the drawing, although they are painted black on most cameras so that it may not be obvious that they are wood. Two retaining bars made from spring sheet metal are fastened to the wooden strips with wood screws. The bars are different dimensions as are the wooden strips. On the right side, the retaining bar is stationary and positioned relative to the wood so that a pocket is formed that runs the length of the long dimension. One side of the film holder is seated in this pocket and the holder then drops down onto the felt surface. The other retaining bar on the left is mounted so that it can slide over the other edge of the film holder.

Since Graflex made cameras of similar design over very long periods, there were small differences in both the cameras and film holders. The first requirement for converting a Graflok style holder is that it be the same width in the short dimension as the area on the Graflex back that receives the film holder. If the Graflok style holder has a base plate with the same dimensions as a Graflex holder for the target camera, then there are two modifications that can be made to make it work with the camera. The two ridges must be ground off so that the base plate surface that faces the camera is perfectly flat. These ridges, in addition to acting as light traps keep the holder from sliding in the long dimension on the camera. The locking action on the Graflex back is accomplished by two small 'ears,' formed in the darkslide end of the pressed metal structure, engaging two companion notched in the film holder. The Graflok type film holders do no have these notches, so they must be cut into the holder.

Note that this modification will make the case of the Graflok rollholder no longer usable on a Graflok back. The strategy should be to create a dedicated, modified rollholder for use on a Graflex SLR and have another one of the same design for Graflok backs you may be using. You can then use the rollholder inserts interchangably between the different back cases.