With these materials the Heian calligrapher--and later the Zen monochrome artist--created a subtle world of light and shade. The preparation for writing (and later, painting) is itself a ritual of almost religious significance. The ink, called sumi, must be prepared fresh each time it is used: a small amount of water is introduced into the concave portion of the inkstone, and the slightly moistened ink block is slowly rubbed against the stone until the proper shade is realized. The brush is soaked thoroughly in water, dried by stroking it on a scrap of paper, dipped into the new ink, and applied directly to the writing surface. The writer or artist holds the brush perpendicular to the paper and spreads the ink in quick strokes, which allow for no mistakes or retouching. Where the male scholars of the Heian period labored with complex Chinese ideograms, the female artists and calligraphers were able to work in a new, simplified syllabary of approximately fifty symbols, which had been invented by a Buddhist priest in the early Heian era. Since this new script was less angular and geometrically formal than Chinese writing, it lent itself to a sensuous, free style of calligraphy whose rules later spilled over into Zen aesthetics. The new "women's script" called for brushstrokes that were a pirouette of movement and dynamic grace, requiring the disciplined spontaneity that would become the essence of Zen painting. Indeed, all the important technical aspects of later Zen monochrome art were present in early Heian calligraphy: the use of varying shades of ink, the concentration on precise yet spontaneous brushwork, the use of lines flexible in width and coordinated with the overall composition, and the sense of the work as an individual aesthetic vision. The lines record the impulse of the brush as it works an invisible sculpture above the page; the trail of the brush--now dry, now flushed with ink--is a linear record of nuances in black across the white space beneath. The total mastery of brushwork and the ink line gave the monochrome artists a foundation of absolute technical achievement, and the Zen calligrapher-poets a tradition of spontaneity in keeping with Zen ideals. Another legacy to Zen artists was the creation of spontaneous verse, which also sharpened the faculties and required a sure mastery of technique. Since virtually all communication was in the form of poems, to move in polite circles a man or woman had to be able to compose a verse on any subject at a moment's notice. A famous female novelist and diarist recalled a typical episode: _The Lord Prime Minister . . . breaks off a stalk of a flower-maiden which is in full bloom by the south end of the bridge. He peeps over my screen [and] says, "Your poem on this! If you delay so much the fun is gone" and I seized the chance to run away to the writing box, hiding my face-- Flower-maiden in bloom-- Even more beautiful for the bright dew, Which is partial, and never favors me.