Paper exposure data for Ilford MGIV RC, FB and FB/WT is available on Darkroom Automation's support site. Although meant primarily for users or DA's f-Stop timer and Enlarging Meter, the data is applicable to all darkroom workers.

Graphs showing the print zone Vs exposure relationship clearly show the effect of each contrast filter.

Darkroom Automation now supplies footswitches for its timers at $29 each: