on saleTWSBI Diamond 50 Ink Bottle - Red

Once you figure the method out (videos were helpful), this is great even on non-TWSBI pens. Saves wasted ink often left in the original bottle the ink comes in.

I was hesitant about purchasing an empty bottle but am very happy my friend and I talked each other into purchasing this. The fountain pen refilling process was mess free and simple. Highly recommend!

I bought this to use with my Diamond 580. With the nib unit detached, the pen barrel fits onto the connection perfectly, allowing for a nearly full, mess free fill. And the bottle looks amazing with my Yama-budo in it. Thanks to Brian & the gang at Goulet

The TWSBI Diamond 50 ink bottle seemed pretty cool when I bought it a little shy of three years ago, but I never got it to work well. There were three basic problems. (It is very pretty, though.)1. It gradually dried out, no matter how firmly I sealed the caps. (The original ink bottles didn't do so over the same period of time.) When that happened, the siphon tube got clogged and was very hard to clean.2. The manufacturer's documentation said that the siphon feature on the middle cap could be used with international converters in addition to certain TWSBI pens. Seating a convertor well was difficult even when it worked, but some manufacturers' convertors wouldn't fit at all (Monteverde in particular). This was a surprise because all the convertors I tried came from pens that can use international cartridges.3. Using the conical reservoir to fill a pen with the nib on was much harder than it looked. I never did get the knack of reliably filling the reservoir by flipping the bottle over. Filling through the nib without the reservoir had no advantage over using the original ink bottle or a cheap plastic inkwell.

Awesome ink well. It allows filling of almost any pen. The only pen I have that it doesn't fill is my gigantic novelty fountain pen.