If a curtain (or perhaps some type of summer garment) had colored and white strips, a nega can spread from one to the other. They asked Rabbi Eliezer about a white strip that has nowhere to spread. He replied that he hadn’t heard anything on this matter. Rabbi Yehuda ben Baseira asked if he might address the question and Rabbi Eliezer replied yes, so long as doing so would support the words of the Sages. Rabbi Yehuda ben Baseira then said that the nega might remain unchanged on the garment for two weeks, and a nega that remains unchanged on a garment for two weeks is ritually unclean. Rabbi Eliezer then praised Rabbi Yehuda ben Baseira as a great scholar for upholding the words of the Sages. Adjoining spreading is impure in any size; distant spreading is impure in the size of a split bean. A nega that reappears is also impure in the size of a split bean.
The warp and woof threads of a loom can contract ritual impurity immediately (i.e., as soon as they’ve been spun). Rabbi Yeuda says that warp threads can only contract impurity after being boiled but the woof threads can do so immediately, and bundles of flax after they’ve been bleached. In order to contract nega impurity, there must be enough in a spool to weave a piece of cloth three fingerbreadths square, both warp and woof, even if the spool is all warp threads or all woof threads. If the spool consisted of broken threads, it can’t contract nega impurity. Rabbi Yehuda says that even if the thread is broken in only one place and was tied to the rest, it can’t contract nega impurity.