An introductory paper by Ralph Griswold on continued fractions as a source of number sequences for weave design. It explains ordinary and simple continued fractions, the sequences for rational, quadratic irrational and other irrational numbers, and how to compute them with Euclid's algorithm. It also covers periodic patterns such as those for tan(1) and e-1. A gallery of continued fraction expansions and three generated tabby and twill weave patterns (from the square roots of 10089 and 9949) hint at later applications. It ends with references and a note that quadratic irrationals will be the topic of the next article.