The most important feature of any inkstone is its grinding surface quality. It needs to be suitable for preparing uniformly thick ink. The finer the ink quality the more pleasant the writing will be. However, this is not the only factor that will help us to decide.

First of all, we choose the inkstone by employing our senses:

• We use our eyes to judge its shape, colour, natural patterns, carvings and decorative motifs, etc. Then we search for flaws such as cracks, scratches, chipping, etc. The best way to examine an inkstone is by submerging it under water, for the stone colour to turn darker.
• We use our fingers to feel its surface. It needs to be smooth and warm like the skin of a baby’s face or that of a beautiful woman. An inkstone with a rough surface has no value, as it will chip the ink during rubbing. Badly prepared ink can not only obstruct writing, but also tear the paper or even damage the brush.
• By pressing a finger against its surface, we examine if the fingerprint is clearly visible and stays visible for a while after the finger is removed. If it does, it means that the stone texture is tight and it does not easily absorb water, thus the inkstone is of a good quality. The same effect can be achieved by breathing on it.
• Finally we use our ears. Holding the inkstone we strike it gently with a fingernail. Generally speaking, good quality suzuri will deliver a clear crystalline sound (though it depends on the stone type). Too metallic a sound will tell us that stone is too hard, and too dull a sound will reveal its excessive softness (though there are exceptions).

Depending on what type of inkstone we need, we pick a different shape or size of stone. Usually, for writing kanji we will use larger inkstones and for writing kana or small size characters we will need a smaller item. For practical uses the inkstone should not be lavishly decorated. After years of use, dried ink that was not completely washed off after writing will most likely cover some of the carvings.

Once chosen and properly taken care of, an inkstone will last forever. If one is serious about calligraphy or ink painting, and wishes to create good quality art, he or she should consider purchasing a superior quality inkstone, that will suit their needs best.