Gelatine hectograph – jelly pad

What is a gelatine hectograph?

A gelatine hectograph, also called a jelly pad, is an early printing and duplicating technology.

In ancient Greek ‘hecto’ means one hundred and ‘graph’ means to write. ‘Jelly’ is short for ‘gelatine’. The term ‘gelatine hectograph’ means ‘to write one hundred copies with jelly’.

How were gelatine hectographs used?

At school in the past, gelatine hectographs were used for printing images directly into students’ exercise books. Everyone in the class had the same image printed in their book.

Today photocopiers and printers are used to print images and worksheets for students.

Gelatine hectographs saved paper, were portable and could be used over and over again.

How does a gelatine hectograph work?

An image drawn using hectograph carbon paper is placed onto the surface of the jelly. The jelly absorbs the image. When a blank page from a book is placed onto it the image from the jelly is transferred onto the page.

A glass tray with clear jelly and a reverse line map of Australia on the surface.

A map of Australia on the surface of a jelly pad ready for printing

Jelly pad recipe

  • 375ml glycerine (glycerol)
  • 250ml water
  • 60g gelatine

Melt all ingredients together in a saucepan over low heat, stirring gently.

Pour into a rust-proof, shallow, rectangular dish and allow to set hard on a flat surface.

The jelly pad can be re-melted in its tray in the microwave or oven if it gets damaged or has bubbles on the surface.

Two boxes of stencil paper, sheets of carbon and stencil paper, a traced stencil of Australia.

Hectograph carbon paper used for jelly pad stencils and stencils used in spirit duplicators

Instructions for use

Draw your stencil

  1. You need a sheet of shiny or very smooth paper and a sheet of hectograph carbon paper. (NSW schools used purple Fordigraph spirit duplicator carbon paper. Thermal tattoo stencil paper is a modern equivalent.)
  2. Place the paper on the desk shiny side up and place the carbon paper on top, carbon side down.
  3. Draw or trace an image onto the back of the carbon paper. This is the reverse of how carbon paper is usually used.

Print using the jelly pad

  1. Lightly moisten the surface of the jelly pad then pat dry.
  2. Place the paper with the carbon image face down onto the jelly and gently smooth it over with your hand. Leave it for 3-5 minutes then carefully peel it off. 
  3. Press a blank sheet of paper onto the image, smooth it over and carefully peel it off the jelly.
  4. About 50 copies of the one image can be reproduced this way before it gets too pale.

Over time the image sinks to the bottom of the jelly, eventually discolouring the jelly. The jelly pad continues to work even when completely purple. Traced stencils can be reused over and over again.

Glass tray with clear jelly in the base. A piece of paper is being pressed onto the surface.

A child pressing a blank page onto the surface of a jelly pad.

The image from the jelly is transferred to the paper.