One of the recurrent problems one faces in buying fountain pens is that, despite hopes and expectations for a superb writing experience, all too often the reality does not measure up. So you've just unpacked your dream writing instrument from the box, inked it up, and are ready to experience Nirvana only to discover that the reality has fallen short of expectations. Now what to do?

Smooth Ride, Skimpy Ink Flow

Suppose that the pen is a smooth writer, but the ink flow is not what you might want. Before you exchange the pen, it's useful to try a couple of simple tricks first.

1. Formula 409 Treatment. Sometimes this problem is caused by ink sticking to the sides of the converter or to various junk stuck in the feed channels. In either case, repeatedly flushing the pen with a mixture of 1 part Formula 409 (or similar products like Fantastik) with 5 parts water can help to lubricate the walls of the converter and clear the junk from the feed. While it doesn't always work, this is a simple and harmless enough fix to be tried.

2. Change inks. In a perfect world, every pen would operate well with every type of ink. Sadly, reality is different. The ink you choose can and will affect your experience. In my experience, the gold standard to test in every balky pen is Waterman Florida Blue ink. This pen has a nice combination of ink saturation and free flow. Thus, it combines the good flow qualities of Sheaffer Skrip (which will write in most any pen but will look badly washed out in pens with stingy feeds) with the saturation qualities of Aurora Blue (which is very saturated but des not flow as well in some pens). If you're using Montblanc ink and not having good results definitely try another---this ink is well-known to not perform in certain pens.

If neither 1 nor 2 fix the problem, it's time to exchange.

Good flow, but bumpy ride

Suppose that the pen writes without skipping, hard starting, washed out ink, or any other flow problem. However, the writing experience has a rough quality to it. You might still try the above two tricks because sometimes  simple increase in ink flow can lubricate the nib sufficiently to produce smoother writing. There are also a variety of small adjustments you might make to the nib itself to get it to write. However, if you're new to fountain pens, are risk-averse, or simply don't have the patience to fiddle forever, this might not be fruitful. Now you're in a situation where you have to decide whether to exchange the nib or not.

When you exchange a nib, what you're basically doing is giving away your nib, with known smoothness qualities, for a draw from the nib "urn" with uncertain quality distribution.

Thus, the question comes down to whether your existing nib is sufficiently bad that you'd rather a random nib than the one you currently have.  This is the heart of the decision process.

The likely quality of the random nib depends a lot on manufacturer. Here's a rough guide:

Pelikan: The quality of a random Pelikan nib is quite high, which means that if you're at all unhappy with the existing nib, exchange offers good prospects for improvement. In the US, however, the service is pretty bad. You will have to wait a fair bit of time to get the nib back and there have been some reports of poor shipping practices and other problems that might give you pause.

Sheaffer: My experience has been that the quality of replacement nibs is quite high. In fact, the average replacement nib seems better than the average fresh out of the box nib. Service is consistently excellent.

Parker: The replacement nibs here are all over the map. I've had good replacements and utter disasters. Service is fast and good though.

Montblanc: Replacement nibs seem to be of high quality, but there is a substantial charge just to even look at the pen. Service is slow.

Lamy: More high quality replacements, but a small charge ($7) for nib swapping in the US. For pens like Safaris, the charge represents a substantial fraction of the original cost of the pen. It seems almost cheaper in these instances just to buy additional nibs rather than to exchange. Service time is unknown.