'Shiro' in Japanese, means white, and is used to describe the 'white metal' color of the stainless steel nibs.
There was no secret metallurgic miracle in Japan that produced 'shiro' nibs. They were ordinary stainless worked into sheets usable for nibs.
They come in very flexible to ultra-stiff.
Some time ago I had several boxes of pre-war pens with 'shiro' nibs. All of the pens were of the same design and came in assorted celluloids and black. All of the nibs were the same in appearance, size, and markings. Trying out each pen, the flexiness to stiffness ratio formed a bell curve with a few real flexible and a few stiff. Most makers did not make their own nibs and relied on other specialty firms for this task. They could not ask for all flexible or all stiff and got what they got. It was hit and miss. Besides, very flexible nibs make it difficult to write intricate Japanese characters and, when these nibs are found today, it may be that they were not used much or didn't sell.
Smoothness, or the ability to flow freely accross a normal piece of paper, formed a sililar bell curve with no relationship between flexiness and smoothness. Smoothness is almost solely related to tip and how it was ground. Because flexible nibs had more give, they did seem to be less scratchy when inked.
Compared to gold, some are as flexible and smooth. Until the 1970s, they were the exception. In the 1970s Pilot developed the techniques and found the better steel needed for steel nibs that were the equal or superior writing ability of gold. Sailor, too, marketed pens with TIGP (Titanium Gold Plated) nibs that were as good as gold. Unfortunately, the market demanded gold and they did not sell as well as hoped.
Despite the reputation of stainless as being rust-proof, they are not and one will see some with minor rust stains. Some are even stamped RUSTPROOF but, one can see they have not withstood the test of time. This is due to the high acidity of some inks.
As with all nibs, one must try them out or take the word of the seller. If purchasing one from eBay or online ask if it is returnable if it is not as smooth as the seller claims.
My personal preference is to go for the gold and only try to buy pens with stainless nibs if they appear flexible or come with a pretty piece of celluloid attached. Sometimes, I'll go for a larger model if the condition is superior. I stay away from eyedroppers as fixing them is not worth the hassle. Unless, of course, the pen is truly collectable.
Check out a few. Don't bid too high and don't get suckered in by the sales pitch. 'Shiro' nibs are not that special.
Edited by stan, 24 May 2008 - 02:29.