[Pen/Pencil Review] The TWSBI Diamond 540
A couple of weeks back my household had debacle with the post office. Much of our mail went astray (some still lingers in limbo). One piece of mail slipped past the Event Horizon to make it into our possession… the delivery of our TWSBI Diamond 540s EF nibs. Jimmy ordered the clear for himself and ordered the Limited Edition ROC red/clear/blue. The ROC was for the 100 anniversary of the Republic of China — our newest niece was born there and the color pattern ROCKS. 
We’ve been waiting for the new TWSBI ever since the announcement of the LAST TWSBI. At first blush, there’s not much different between the 530 and the 540. The 540 clocks in at the same length – 5.5″ capped, 6.75″ posted. For the most part they share the same body. For those who are just that handy – the 540 (like the 530) can be completely disassembled and reassembled for thorough cleaning and or repair — or even nib replacement. Each 540 comes with a wrench and silicon to perform routine maintenance.The most noticeable difference? The ink reservoir. 
Both have the TWSBI piston ink-filling system. The whole back end of the pen is the piston crank on both the 530 and the 540. However, if you measure with a ruler (because I’m not sure what it actually calculates out to in ml or area), the 530’s reservoir takes up .75″ of the length of the barrel. The Diamond 540’s reservoir is just under 1.25″ – which means it should write much longer between refills. How is that possible? Part of the piston filling system is less bulky in the 540 than the 530. They’ve condensed part of the piston mechanism to make more room in the reservoir.
The Diamond 540 continues to have the TWSBI balance and feel that I’ve come to expect with the 530. The nib is solid but flexible with continuous writing. We order the EF nibs – I like a fine line with no skips. TWSBI provides that. 
We both like the weight and balance of the pen – I write with the pen posted. Jimmy does not. I like the length. Jimmy finds it a little unbalanced for him. I don’t have that problem. Whether you like a long pen or not, the TWSBI is well-balanced either way.
I’ve loved the 530. I love the 540. This pen – the 530 is sold out – runs $50 – $60 (the ROC anniversary pen was a little more expensive). They’re only available online, which may make them tough to find and order. But they are solid, dependable pens at a decent price point for those who give them a good work out or collect.
I give them 4.5 bronze pencils.
