Creating Rubber Stamps: Not All Methods Created Equal (Part 2 of
3)
Welcome back! In part one of this three-part series, the
advantages and disadvantages of laser-engraved rubber stamps
were discussed. As discussed in the first article, although
laser engraving has a high start-up cost, its quality and
efficiency are second to none. In this segment, you will learn
the benefit and fallbacks of a photoengraving stamp-making
method.
Making a rubber stamp through a chemical or photopolymer process
will also require significant start-up costs. Depending on the
equipment capabilities, quality, or size, a photopolymer
stamp-making kit may cost anywhere from $400-$4000. This process
requires a significant amount of labor and tends to have a
higher turnaround time.
The first step of the photopolymer process involves creating a
negative of the image to be engraved. To begin, create or obtain
a completely black graphic on a completely white background. If
the graphic has colors, save or convert it to a monochrome or
two-color format. A simple graphics editor, such as Paint (which
automatically comes with a Windows OS) will allow the user to
"Save As" and choose a "Save as type" as "Monochrome Bitmap."
This will convert the colored graphic into a black-and-white
bitmap file. Once the image is completely black and white, using
a graphics editor (again, Paint will work), invert the colors.
This will create a white image on a black background.
Turnaround time for a rubber stamp will vary greatly, as this
variable is contingent on the creation of a metal plate. If you
are creating stamps for fun, you will need to have enough
graphics to fill both a metal plate and a matrix (mold) board.
The metal plate and matrix board can be made on a partial board;
however, this is not an efficient use of materials and may make
for uneven molds and/or stamps. If maximum efficiency is
desired, enough graphics will need to be obtained to create a
full metal plate. Additionally, the photopolymer process does
not allow small businesses to make custom rubber stamps
efficiently, as these rubber stamps tend to be made for a
one-time order and the mold is no longer needed.
Depending on the materials at hand, the metal plate may need to
be made by an engraving company. Once the metal place has been
engraved, it is placed in a machine with the matrix board and,
with a combination of heat and pressure known as vulcanization,
the matrix board is made into a mold. The rubber is cut to the
size of the mold, placed in the vulcanizer, and creates a rubber
stamp through a similar process of heat and pressure. Be warned:
as a mold is put under heat and pressure every time a rubber
stamp is created, it may only last for 40-60 stamp
vulcanizations.
After the rubber has been pressed, it can be cut into individual
stamps. As the rubber is quite thick, most stamp enthusiasts
agree regular scissor are not sufficient. Kai Scissors are a
considered an essential tool in the arts and crafts world. These
scissors can be found at crafts stores or on the web, and Kai
Scissors makes 15+ styles and sizes of scissors. Mounting foam
is also needed to ensure the block the stamp is mounted on does
not come in contact with the surface to be stamped. Once the
rubber and mounting foam have been cut, the stamps are glued to
a wooden mound and are ready to impress!
We have discussed laser engraving, photoengraving, and one last
stamp-making method is yet to come! Next, learn how to make
rubber stamps, without any special or expensive equipment, from
the privacy of your own home!