In all sections there was a greater variety of forms and designs than in the preceding period. Designs were no longer confined to the interiors of bowls and ladles but were placed on all kinds of vessels. Basketry patterns were still used, but others were taken from textiles, and still others seem to have been developed only for the medium of pottery. Designs show a certain lack of skill in execution, but they were elaborate and boldly conceived. There is every evidence of people still experimenting with a new medium. The principal elements were parallel lines, sometimes straight and in other cases stepped or wavy; zig-zags, triangles, checkerboards, and interlocking frets. Both curvilinear and rectilinear designs were used. In the latter part of the period parallel lines were scarce, and elements became broader and heavier. [Illustration: Fig. 23—Black-on-white pottery. Developmental-Pueblo period.] [Illustration: Fig. 24—Neck-banded vessel. Developmental-Pueblo Period. (Courtesy National Park Service.)] Techniques of production and finishing differed from those of Modified-Basketmaker times. The practice of using slips developed. A slip is a coating of very fine, almost liquid, clay which is smeared on a finished vessel before firing to give a smooth even finish. In the second part of the period, spiral coiling began. In the earlier forms, short clay fillets, which made only one turn around the vessel, were used. With the spiral technique, longer rolls of clay were used and each made several circuits around the vessel. During the first half of the period, vessels were either entirely smoothed or, in the case of many culinary vessels, the bottom was smoothed while the neck portion was characterized by flat, relatively broad, concentric clay bands. These neck-banded jars are quite characteristic of early Developmental Pueblo. During the second part of the period corrugated ware appeared. This is pottery in which the alternate ridges and depressions resulting from a coiling and pinching technique of manufacture have not been obliterated. Sometimes the corrugations were embellished by indentations produced by pinching the clay between the fingers or by incising them with the fingernail or some small implement. In this way simple patterns were formed. The use of this type of pottery for cooking may stem from the fact that this is the only type of decoration which would not soon be obliterated by soot. Objects made of clay also included tubular pipes or cloud-blowers. Stone and wood were also sometimes used in making these objects.