in a variety of sizes. Ink and inkstick Ink is made from lampblack (soot) and binders, and comes in inksticks which must be rubbed with water on an inkstone until the right consistency is achieved. Much cheaper, pre-mixed bottled inks are now available, but these are used primarily for practice as stick inks are considered higher quality and chemical inks are more prone to bleeding over time, making them less suitable for use in hanging scrolls. Learning to rub the ink is an essential part of calligraphy study. Traditionally, Chinese calligraphy is written only in black ink, but modern calligraphers sometimes use other colors. Calligraphy teachers use a bright orange or red ink with which they write practice characters on which students trace, or to correct students' work. Inkstone Commonly made from stone, ceramic, or clay, an inkstone is used to grind the solid inkstick into liquid ink and to contain the ink once it is liquid. Chinese inkstones are highly prized as art objects and an extensive bibliography is dedicated to their history and appreciation, especially in China. Seal and seal paste Calligraphic works are usually completed by the calligrapher applying one or more seals in red ink. The seal can serve the function of a signature. Technique The shape, size, stretch, and type of hair in the brush, the color and density of the ink, as well as the absorptive speed and surface texture of the paper are the main physical parameters influencing the final result. The calligrapher also influences the result by the quantity of ink/water he lets the brush take up, then by the pressure, inclination, and direction he gives to the brush, producing thinner or bolder strokes, and smooth or toothed borders. Eventually, the speed, acceleration and deceleration of the writer's moves and turns, and the stroke order give "spirit" to the characters by influencing greatly their final shape. The "spirit" is referred to yi in Chinese calligraphy. Yi means "intention or idea" in Chinese. The more practice a calligrapher has, his or her technique will transfer from youyi (intentionally making a piece of work) to wuyi (creating art with unintentional moves). Wuyi is considered a higher stage for calligraphers, which require the calligrapher to have perfect control over the brush and wrist and following his or her heart. Study Traditionally, the bulk of the study of calligraphy is composed of copying strictly exemplary works