In article <4925c0$s8q@quepassa.lirmm.fr>, jappy says...
>Can anyone give me information on grafmatic backs? In particular, I >would like to know how they work, who makes them, and how much they >cost. Any personal opinion on them (film flatness, bulk, weight ...)
>is also much welcome.

Grafmatics are my prefered holders for 4x5 film - they take up half the space of two-sheet holders, they are easy to load and unload (if you
are careful and organized about it), two holders contain one [12 sheet] tank full of film, they scratch the film backs less than two-sheet holders, they hold the film securely and very flat, and they are very reliable IF you NEVER operate them rotated so that the darkslide pulls
at an angle below the horizontal (they will jam if a platen slips down-hill while in the forbidden position, and the platen will be bent in the process). Bent platens can (and must) be straightened before use
(the small clips that hold the sheet of film can also be adjusted so that they lightly grip the film - and the side rails should just pass the film as it is slipped into the platen). They should operate fairly smoothly (car wax can help on body edges), but they do require a steadying hand on the camera while being operated to keep the camera from being moved or the holder from slipping out of the camera back. Grafmatics are no longer made and are available only used. Used Grafmatics go for $50-$100 each here. To operate:
To load - move the counter to "X", grip the darkslide while pressing
the chrome lever toward the darkslide handle so that it catches on its edge; pull the body of the holder out of the shell until it stops; push the darkslide toward the body the short distance needed to release the chrome lever from the darkslide handle; pull the darkslide until it stops; remove the stack of platens, the end of which pops up past the end of the darkslide when it is withdrawn to its stop; place the stack of platens on a clean surface, put one corner of a sheet of film over the platen surface, draw it toward you in contact with the surface
until the near edge of the film is caught by the nearer side rail of
the platen, straighten the film relative to the platen as you turn the platen load-edge up, catch the other edge of the film under the other rail, let the film drop into the platen, press the edge of the film to seat it under the clips at the bottom of the platten, place it CAREFULLY on the stack of loaded platens; take the stack of 6 loaded and lined-up platens and put them load-edges first into the body of the Grafmatic, press the end of the stack (by the edges) that is sticking up far enough down so that the darkslide can be slid over the stack; close the darkslide; slide the body back into the shell; and turn the counter to "1" (it is all MUCH easier than it sounds!).
To use - insert the Grafmatic into the camera (it may not fit a few older field cameras because of the thickness); hold on to the edge of the camera back to steady the camera and prevent the holder from coming out; withdraw the darkslide to its stop (you will hear a platen move forward); push the darkslide BACK IN (it prevents the other sheets in the holder from being fogged!); expose the film; pull the chrome lever over to catch it on the darkslide handle and pull the body out to its stop (you will hear the exposed platen move to the rear); push the body back into the shell; remove the holder from the camera (DO NOT do any of this with the handle end of the Grafmatic below horizontal, or damage will result [down angle on the camera is fine - just not down rotation of the handle side of the holder]); the mechanism will lock after 6 sheets to prevent reexposure of earlier sheets.
Hope this helps.