How Rubber Stamps Are Made - Rubber Stamp Supplies

How Rubber Stamps Are Made
Vicki Davis
Stamping Sensations

I have always been fascinated by the concept of cyclical processes - when a thing can come full circle and tap itself on the shoulder. That happens in many arenas, but, here it is really obvious.
A rubber stamp must begin and end as the very same thing - a sharp and clean, black and white image. The process begins with artwork in black and white. In the end, if you test the stamp you have made with black ink on white paper, it should produce an image identical to the one you started with. During the process, there are so many flips and flops between positive and negative versions of that image that it gives the right brain conniption fits when it turns out to be itself. Now that I have made it so confusing, let Vicki make it simple:

Making the Art:
Artwork is arranged on sheets to fit as many images as possible, and still leave room for trimming. The images must be very sharp and distinct, in black and white, and right reading - meaning that they look as they should when stamped.

The Plates:
There are actually three steps involved before you get to the rubber. First, a film negative is made photographically from the art. This is used to produce a metal master plate which is usually made by an engraving company. This is done with a chemical etching process, and the deeper the etch, the higher the rubber image will stand up away from its background. This is why you hear people refer to“deep etch” stamps.

The metal plate is used to make a matrix board, a kind of negative plate that is made in the same machine, a vulcanizer, that is used to press the rubber (right, below). The rigid, smooth, matrix board is placed in the vulcanizer with the metal plate, and, with heat applied, the matrix material softens, and the images on the metal plate are pressed into the surface of the matrix board, which becomes rigid again when cooled.

Pressing the Rubber:
Rubber comes on big rolls and must be cut to fit the plate size. Vicki uses a Kai Scissors for this because rubber does not cut easily with regular scissors.

The cut sheet of rubber (with a release sheet) is put into the vulcanizer with the matrix board which now carries the stamp images. Heat and pressure are applied, and voila - you have a sheet of unmounted rubber.

Vicki uses a matrix board to measure a same size sheet of rubber. The two are then put into the vulcanizer with a release sheet, and are heated and pressed.
Unmounteds:
If you are selling your images unmounted, you have but to trim (Kai scissors) and package them. Many manufacturers choose to arrange images that go together on a sheet , and sell the uncut sheet of rubber as is.

Wood Mounted Rubber Stamps
To produce mounted stamps, several more steps are necessary. First the rubber sheet is attached to mounting foam. Then, most manufacturers use a scroll saw to make clean cuts around the images (Angi is doing that below left), and the cut-out image is attached to a wooden mount.

The wood mount then needs to be indexed, which means that the image is stamped on the top of the mount so that the stamp can be easily identified. Because the stamp will be handled so much, the index image must be waterproof and immune to wear and tear as much as possible. Vicki uses printer’s ink, which is pretty messy, but does the job well (below right).

Ink from the can is brayered onto scrap paper. The unmounted image is then mounted temporarily on an acrylic block (so she can see exactly where it is going), inked by tapping on the brayered paper, and stamped onto the wood mount. Manufacturers use an extra of each image to do this job because the printer's ink is permanent and the stamp used with it could not be sold.

So, that is the story of how a rubber stamp comes into this world, and, as we all know, once it leaves its place of birth, and gets into our hands, there's no telling what adventures lie in store for it!