AN oft repeated error is in play here. Yes, dilute paper developers work with lith type films, but not nearly as well as dilute film developers. Paper developers by their nature are more active and will produce more contrast than film developers.An inter-positive needs to be very low in contrast. It should have grayish highlights and very open shadows. This is quite easily done if film developers are used. D23 works well, as do D76 diluted one to five, and HC 110 diluted one to 20 from stock.