Stamp-Making Methods

Although there are several variations (self-inking, impregnated rubber), the "old fashioned hit the ink pad," or traditional handle/moulding type is still far and away the most popular -- and is likely to remain so for the future. Making rubber stamps can be both interesting and profitable.

There are at least ten different modern methods for making rubber stamps (in addition to ancient, original hand-carving) and anyone considering this as a business know about them.

#A Hand-Carving (Ancient Technique)
#1 Hand-Set "Foundry" Method
#2 Negative Type
#3 Linotype Method
#4 Hand-Carving Revisited: Eraser or Polymer
#5 Engraved Negative Mould
#6 The Industry Standard: Photopolymer
#7 Mass production with Vulcanized Rubber Stamps
#8 An Industry Standard Alternative: Laser Engraving
#9 Liquid Polymer Rubber Stamps
#10 Silk-Screen Adaptation to Photopolymer (FastLight Method)
Afterward

The oldest method is hand carved type, which is still used today in the orient - Chinese in little stalls on the streets of Taipei for example will hand carved your "han" (Chinese family name) into a rubber stamp for a few cents, or into an ivory or bone han for a little more.

Not long ago, it was possible to have a genuine signature stamp made this way. It took one of these artist (who speaks Chinese) about 10 minutes to carve a complete signature (in any language) from a carbon (backwards) copy -- at a cost of less than a dollar. A similar art is still practiced in this country - but more on that later.

The most common method of making rubber stamps is with hand set "foundry" type. Individual printer's type is hand-set, along with any borders or illustrations (cuts) into a holder (chase).

The stamp maker inserts the letters, spaces (ems, ens), lines and line separators (leads) and any fillers into a reverse image of the desired stamp. All of the letters, etc., are "type high," a standard term meaning equal height so they will protrude from the chase to make a uniform impression.

When assembled, the chase is tightened to hold the "copy" firmly in place and a trimmed piece of specially treated, plasticized board (matrix) is placed over the design. The chase and matrix are then placed in a machine that applies measured heat and pressure which gently squeezes the layout in the chase into the matrix and leaves a positive impression of the desired stamp in the matrix, which is allowed to cool and cure.

Since matrix is a thermosetting plastic, it can be molded only once; it will not soften when re-heated. Raw rubber is then cut to size and pressed into the matrix by the same heat and pressure machine. When the rubber is "cured" ( 2 or 3 minutes), it is trimmed, glued to a mount, and PRESTO, a rubber stamp! During the molding process, powder is used to prevent sticking -- and plain baby talc works great.

The second method is very similar except that NEGATIVE (not foundry) type is used. This type is the same size (type high) as the former method, but much more expensive.

With negative type, the finished rubber stamp is formed in a single molding operation; there is no need for matrix or a second heat stage.

The disadvantage is cost and the fact that negative type tends to stretch (due to heat and compression in the chase), which produces uneven letters on the stamps. This method is recommended only for single and "rush" jobs.

Third is the use of the really old fashioned linotype molding machines (e.g., Ludlow) that actually mold a newspaper column width line of type at a time.

This used to be printing industry standard and works fine for rubber stamps, but is quite cumbersome.

There are a few around today only because newspapers and other printers have sold (or given them away) to upgrade to modern printing equipment) these machines use molten lead, are quite large, and understandably generate a of more heat.

When you type a line, molten lead is forced into its internal molds to produce a standard line of type, in whatever style molds that have been placed in the ma chine.. Once the line of type is cooled, it is placed in a chase and made the same way as foundry type stamps.

The fourth is the same general idea as the Chinese "han" carver, and is not used by professional rubber stamp makers in this country. It is the art of hand-carving designs, logos, etc., into a large eraser (especially art-gum) or polymer, then using it as "stamp art."

The official publication for this type of stamping is RUBBER STAMP MADNESS ( see Business Sources), which contains helpful hints, ads and subjects of interest to enthusiasts.

The fifth method is seldom used anymore, except by stamp makers who are also engravers, but it is worth of mention to those who also engrave.

Using phenolic plastic which will stand up to heat, the operator engraves the design as deep as possible into the plastic (like a plastic name tag, or the bank teller's sign). The plastic is dusted with baby powder, a strip of stamp rubber applied, and the combination placed in a heated stamp press.

Since the impression is negative (just like negative type), the finished stamp can be molded direct.

These stamps usually do not have deep letters compared to the type molded varieties, but can be made fast. They might be nice when customers want the same logo on a badge and stamp. It only takes about 10 minutes to cut a name ( for example) into a piece of phenolic and then mold a rubber stamp into it.

Some have done quite well with this system setting up in shopping malls.

The sixth method involves photo processing and requires a larger investment, but it represents the rubber stamp industry's of the coming age.

It is rapidly replacing the other methods because it is cheaper, faster and much more versatile. These rubber stamps are not rubber at all -- they are PHOTOPOLYMER. Most look like clear plastic, although colors can be added to disguise their appearance.

In this process, a facsimile (picture) of the desired stamp is typed, printed or even drawn onto a sheet of paper and photographed (or exposed onto film). The image is then placed in a machine that exposes a light sensitive plastic gel (polymer) in sheet or liquid form (the plastic "sets" only where light strikes it). The entire underside is exposed, and then the top is exposed, and then the top is exposed through the film with the desired stamp design.

After a few moments of cure time, the exposed polymer is washed (most is water soluble) and cut up into individual stamps (most stamp makers do a full page at a time). In the washing process, the raw (uncured) plastic simply washes away, leaving a 3-D impression of each facsimile, which becomes a "rubber" stamp.

Obviously, anything that can be put on paper can be made into a rubber stamp with this process: regular type, Illustrations, even signatures!

Photographs can also be made into rubber stamps with this process as long as there is sufficient contrast.

Method seven produces the traditional red rubber stamp that everybody is familiar with: manufactured in a vulcanizing press. The first rubber stamp vulcanizing press was patented in 1890 by Charles Schultze in New Orleans USA. Vulcanizing is today one of the most cost effective methods of making rubber stamps for mass produced stamps. Each batch of stamps is produced using a mould. This method of manufacture is more suited to stamp making where the same moulds are used over and over again. Making custom made stamps with a vulcanizing press requiring 'once only' moulds will drive the cost of manufacture up significantly, and so this method is not at all cost-effective for custom-made stamps such as address or signature stamps. It is most effective for "stock" stamps such as those with the words "DRAFT," "COPY," "FAXED," "FILED," etc.

Making the mould - before a mould can be made you must have a master plate manufactured from metal or polymer, the master plate has the necessary relief (the artwork is raised) to make an impression in the mould. Having a master plate made each time a mould is required is what drives up the cost of manufacture for vulcanized stamps. Pressing the master plate into a Matrix board creates the mould that will accept the rubber. Heat and pressure is applied to the master plate and matrix board inside a Vulcanizing press. The Matrix follows the shape of the relief provided by the master plate, this then hardens on cooling.

Making Rubber Stamps - Creating stamps is a simple process once the mould is made. Raw rubber stamp gum is placed on top of the mould and then placed inside the stamp press. Hydraulic pressure is placed upon the rubber and the mould from within the stamp press causing the rubber to melt into the areas of the mould that contain the images and text, curing and hardening takes about 10 minutes. Once cured the sheet of rubber is pulled away from the mould and cut up into individual stamps to be affixed to mounts.

The eighth method is exceptionally clean and accurate, albeit requires a pretty hefty investment: a laser engraver. Laser engraving is quickly emerging as a second standard in custom stamp making, as it requires no negatives and no chemicals except for a mild soap solution to wash the final product and eliminate laser engraving odor. In fact, laser engraving material is also advancing, and there are new low- to no- odor laser rubber sheets now available (yes, right here at MSM Marking).

In addition to a laser engraver ($15K to $20K used or 30K+ for a new laser machine), a filtration system is often required for health and safety reasons, which is an additional few thousand dollars for the vacuum pump, filter box, filters, and conduit (tubing) to run the exhaust out-of-doors. And, of course, a computer is required to send engraving jobs to the laser engraver, much like a print job is sent to a laser printer.

The laser engraver functions much like a laser printer and simply "scans" the laser back and forth across engravable laser material, literally lasing (cutting) out a very precise copy of the image you sent to "print" from the on-screen computer. The exhaust system vacuums out the resulting smoke and debris, and you are left with a beautiful, laser-quality engraved piece of rubber, ready to cut, clean and mount into the stamp.

The depth of the engraving is determined by the laser speed, its wattage and the density of the rubber. For example, a 50 or 100W engraver will engrave the rubber deeper and faster than a 25W machine, which may require a second pass to achieve a similar result. Usually supplied in an A4 size sheet form, a good quality laser rubber is required for engraving stamp dies and must also have suitable compression strength and ink transfer properties. As mentioned, MSM Marking is a distributor and supplier of superior quality engravable rubber stamp material.

Converting rubber stamp polymer from a liquid into a solid to make stamps is quite fascinating. Polymer stamps are manufactured between two sheets of glass using precision controlled UV light which passes through a negative containing the stamp artwork solidifying the polymer. Negative production has been simplified with the introduction of water based negative technology, photographic chemicals for producing negatives are now a thing of the past.

The first step in making polymer rubber stamps is to print your images, clipart or text onto Vellum, an almost transparent paper like film.
To produce quality stamp artwork you must use a laser printer, inks from bubble jet printers are translucent allowing UV light to pass where it should not. Water based negatives are easily washed out after being exposed for a few minutes in a UV exposure stamp machine.

Polymer contained in a sachet is now replacing the older cumbersome method of using foam tape to create a dam and pouring of rubber stamp polymers, the sachets have also addressed the age old problem of removing air bubbles from the poured polymer.

The negative of your artwork and polymer sachet is sandwiched between two sheets of glass spaced 2-3mm apart which is then exposed in the machine for a few minutes. Once you have completed the exposure it is a simple process of cutting open the sachet and washing away the excess unexposed polymer before returning the stamp die back to the machine for a 10 minute curing. Once the stamps are cured they can be cut up individually. Polymer sachets are available in a range of sizes up to A4 size.

Processing time is about 30 minutes for a batch of polymer stamps.

The tenth method is a scaled down version of the sixth and ninth methods, combined. It is essential a silk-screening technique adapted to photo-sensitive polymers. As other methods became more expensive and better suited toward mass production, this evolved as a relatively inexpensive alternative to getting professional results with a much smaller investment. This method skips the film exposure and allows a stamp maker to directly transfer a laser printed image onto the photo-sensitive stamp polymer surface. This is one of the stamp-making methods here at MSM Marking, and is marketed under our FastLight brand label.

We have a set of videos and also a text instruction page featuring this method, as we believe, while it is not the cheapest, it is the fastest and cleanest method, requiring no moulds, polymers, chemicals, negatives, engraving, or even a large space. An inexpensive computer and laser printer, software as simple as a word processor (which often allows the import of art and graphic), together with a FastLight machine and start-up supplies is all you need to make a near laser-quality-engraved stamp. If you can print it on a laser printer, you can make it into a stamp using the FastLight method.

The laser printed sheet is stapled or taped to a sheet of velum, which is then carefully aligned and placed onto the blank stamp surface. With a few quick flashes of light from the FastLight machine, the laser print is transfered through the vellum onto the stamp surface. That's it! You then seperate then peel the vellum from the previously blank stamp surface to reveal a perfect copy of the laser print -- now a genuine stamp impression. All you do is add ink, wait a few minutes for the ink to permeate the polymer, and it's ready to stamp.

Marketing rubber stamps is almost as varied as the manufacturing methods. You can retail them through advertisements (local or mail order), specializing in one size and type style, or wholesale to local stationary stores.

A typical three line stamp retails in local stores for about $4.95, but will be offered in mail order magazines for 42.95 because the marker specializes, takes a couple of weeks to get your stamp to you, and gets a little extra for "postage and handling."

You can produce self-inking stamps simply glue the rubber impression into a $2 self-inker), notary seals with a special chase and cut; or contract with large companies to make all of their stamps.

Wholesaling involves a discount of 25 to 40 percent, but the retailer does much of the "work" in exchange for his share. The cost of making a three line rubber stamp is approximately 35 cents, plus 5 or 10 minutes labor.

Once a rubber stamp business is established, there are many "sidelines" that can make much more profit with little more investment in either time or money. You could handle embossers (take orders), specialty advertising, stock signs, and desk plates.

The same people who buy your rubber stamps will also be in the market for other products that go with starting or running a small business, and they are already there! Find out what those other products are and add them to your "line."

Something to watch out for in the rubber stamp business is misspelled words and incorrect copy. When taking an order, be especially careful to get it exact.

When setting up a stamp, keep a copy of the order in front of you, and double-check it "religiously." Also, keep a good dictionary handy and use it whenever there is any doubt.

It is also important that your finished stamps look good. Make sure the ends of the stamp mount molding are smooth, that the copy you stamp in the window on the stamp is clear, straight and well centered.

These are little things, but they are very important. They can make your business successful, no matter what your stamp-making technique.