The people at Colop have very kindly sent me one of the e-mark handheld printers (and lots and lots of extras) to try out.
The e-mark is a wireless, palm-sized printer, not much bigger than the standard HP Inkjet print cartridge it takes. It’s programmed wirelessly via an app (Android and iOS) or via a desktop app, with the option of connecting the e-mark’s tiny little hub via USB to the computer.
So, what’s it for? To begin with, the e-mark is a 21st-century replacement option for the inked stamps Colop have been manufacturing for 40+ years. Date stamps, return address stamps, “Thanks for your custom” stamps, and all that kind of thing. Anyone who has ever bought something from Etsy, or purchased a zine like Hellebore (with its infamous Witches Still Live stamp on every envelope) know how cool it is to receive something which has had that extra, personal touch added to the packaging with a stamp.
The e-mark gives to the power to create your own personalised designs, up to three of which can be stored on the device at any given time. This means you can load up your designs and take the e-mark with you in its neat little protective carry case, and print any of them at any time directly from the device. The colour of the e-mark‘s in built lights indicate which of your saved designs (imported into colour coded slots via the app) are ready to print at any given time. You will, however, need to have the app on your phone (at least) to switch between these banked designs.
The e-mark can print a design across as many as three lines – the device beeps to let you know when you’ve come to the end of a line, then beeps again to let you know when you’ve moved it down enough to begin the next line. You can print left to right, or right to left and the e-mark knows what’s going on automatically. Pretty impressive, right? 
What the e-mark cannot do, is split a single image across those three lines, since there is a gap between each line of printing, so that is worth bearing that in mind. It also takes a bit of getting used to to make sure you’re printing straight, especially when you’re printing on more than one line, so it’s best to use a the e-mark ruler, or some other type of guide, to make sure you’re not going off course.
Now, it’s worth mentioning that the way the e-mark connects wirelessly is via its hub acting as a WiFi hotspot, so the device you’re using cannot be connected to the internet at the same time as sharing designs to the e-mark. This can be a little tricky to get used to at first, and can result in having to disconnect and reconnect between your own WiFi and the e-mark as you’re trying to get things downloaded and then imported to the printer. I’ve found that using the desktop app and connecting the e-mark via USB is the easiest way of doing things for me, but iPad is probably the best on the fly solution.
What else do people use stamps for? Well, obviously, the possibilities are pretty much endless. Something I thought I’d have a crack at was a little EX LIBRIS design that could be printed directly into the front of books. I’m using Canva as a quick, online, way of creating designs, which I’m then importing as images to the e-mark. This is a three line print, so the top left frame and EX LIBRIS are line one, the book is line two, and the line and bottom right frame is line three. Obviously, I’ve thrown this together pretty quickly, but you get the idea.
Beyond acting as an infinitely customisable stamp, the e-mark has a ridiculous range of other potential uses which can basically be summed up as “printing jobs which a conventional printer could not do”.
The e-mark will print on any absorbent surface you can swipe it across. I can be used to print wristbands, labels, (continuous, 
repeating) patterns on ribbons, business cards; a genuinely mind boggling range of things.
What haven’t I mentioned? Multi-colour printing in 600 dpi, up to 5 hours of battery life when continuously printing, automatic numbering features (are you producing a limited run of something which you were planning on hand numbering as 1/100, 2/100, etc?), QR code generator… there’s a lot. It does a lot. I recommend you visit the Colop YouTube page to check out some videos on all the possibilities.
The e-mark handheld printer is available now from Colop for around €299 (excluding VAT)