For the demonstration at Tyler School of Art, this large tray was filled with 20 gallons of gelatin. The surface can be painted on with various media to create monotypes. A sheet of Rives BFK was placed on the gelatin, and rubbed by hand to print
Scratching with a broom
The broom print
Workshop participants giving hectographs a try
An example of a hectograph print-rubber stamps were used on the gelatin surface for these prints
The demonstration presenter, Shelley Thortensten has more information on her website
about hectograph, images, and recipes for making the gelatin pad.
I would love to play around with this medium, and offer a workshop in the near future. Let me know if you'd like to give hectograph a try too!