harvest:

Bosses should encourage workers to take big chances, even if it means they crash and burn from time to time, says Tracey Matura, general manager at Mercedes-Benz USA’s Smart car unit. Workers need to know their bosses would “rather pull you out of the wall than have to push you through it,” Matura explains. “The wall hurts everyone, but if you stop short every time you see the wall, we don’t really evolve.”

I spent yesterday shopping around online for rubber stamp makers here in Singapore, and ended up learning a fair bit. There are a few types of “rubber” stamps that can be easily found here, each using a slightly different idea:

• Rubber stamps (confusingly named, but actually, non-inked stamps)
• Self-inking stamps
• Pre-inked stamps

Rubber stamps (non-inked stamps)

Let’s start with the easiest, yet most confusing, of the lot. These stamps need to be tapped on an ink-pad before stamping. The idea is that certain parts of the stamp substrate are recessed and thus won’t pick up ink, making the correct impression[1] on the surface. Have you ever carved a potato? That’s the most basic non-inked stamp.

Non-inked stamps are the cheapest as they’re made of a stamp die[2] and a lump of plastic to hold the stamp die. You might also see wood blocks or acrylic blocks being used instead. Same idea – just something to hold onto, and to paste the stamp die on.

Maybe you’ve played with those red-coloured rubber stamps before as a kid. Those are the ‘real’ rubber stamps, made of vulcanised rubber.

Vulcanised rubber

Vulcanised rubber requires a matrix mold and very expensive equipment to create the conditions needed to mould the rubber into the stamp die. The mould creates a high setup cost since one needs to be made for each design; this method of production is cheaper for very high volumes, but a definite no-go for one-off or small volumes.

Alternatively, vulcanised rubber can be laser engraved, but that also requires a relatively costly Epilog (or similar) laser engraver. Using a laser engraver would also require vector artwork, which I bet most clients would be unable to provide. This would be feasible for making high-quality rubber stamps, but because the artwork is harder to provide for most clients, it’s less available. Most shops save the laser engraving for metal stamps like common seals.

However, these non-inked stamps can also be made of materials that aren’t rubber – such as photopolymer – which stampmaking shops still refer to as ‘rubber stamps’. (Confusing, right?)

Photopolymer

Photopolymer looks like a clear plastic, but is pretty hard and about as nonpliable as rubber – if you poke very hard, it’ll move, but not easily.

It’s made from a liquid polymer that is cured by exposure to UV light. This technology is what allows stamps to be made while you wait (15 min? 1 hour?) because setup is fast and the actual curing doesn’t take very long with a proper light source.

Setup consists of turning the design into a printed out stencil – so the setup cost is really cheap. Thus, you can get this sort of stamp made with any graphic that you want, assuming that the details are not too small that they’re lost, just like screen printing. When a stampmaker by default asks you to supply words or lines instead of an image, it’s to make it easier for most of their clients – there’s no technical limitation that only allows characters to be put on the stamp, apart from having to scale the image down to the size of the stamp die.

Custom non-inked stamps are usually made of photopolymer, because it’s relatively fast, cheap and easy to produce. It’s essentially the only way to get one-off stamps made affordably. Prices should start at $5 for a small one. Yes, that cheap.

Self-inking stamps

These are the boxy, push the top half of the box down stamps. They contain an ink pad at the top, which is where the stamp surface rests when not in use. Once pressed, the stamp flips over while moving down to meet the surface, and when released, it flips back to touch the inkpad.

These cost a bit more, because of the box assembly and included inkpad.

Photopolymer

For custom made self-inking stamps, the stamp is probably made of photopolymer. Just find one and press it down to look at the stamp die: it’s one large piece of plastic thing mounted there that has letters poking out of it. There’s also another material, silicone, that comes into play here:

Silicone

Silicone is much more flexible than rubber, and is the grey stuff that you find in those pick-and-place DIY stamps. You know those kits which come with letters and a 3-line holder? Silicone is a poor choice of material for non-inked stamps, as it can’t stand the pressure of humans stomping the stamp down and will deform, causing smudgy and blurry impressions.

However, for these self-inking stamps, silicone is suitable since the box mechanism of the self-inking stamp stops you from mashing the silicone into the surface.

You’ll hardly find silicone being used for custom made stamps though, since it needs to be moulded like vulcanised rubber.

Pre-inked stamps

These are the ones which have no visible ink-pad – the ink is stored in the stamp surface itself. The stamp die itself is made using ‘flash’ technology, similar to photopolymers, but using a different membrane material.

This stamp involves the entire assembly from handle down to stamp die: the ink reservoir is topped up from the top of the handle. This is the most expensive of the commonly available custom stamp types, since you need to pair it with a suitable stamp holder/handle assembly.

These are expensive, they start at $15-20 for the smallest sizes.

Conclusions?

It’s pretty confusing, but if you know what you want before you go in, you’ll be fine.

I got a non-inked stamp made though. It’s cute.

[1] Impression: the image you make on the paper or whatever surface.

[2] Stamp die: the actual surface which has the ink. The rest of the stamp is usually just for you to hold this die, except for pre-inked stamps.