Originally Posted by coffeegirl
Can I just add a question...
What if I find a substitute which has same gauge as the pattern but the pattern calls for one size needle and the yarn calls for another. So e.g. the pattern says to use 6mm needles and the yarn substitute says to use 8mm. BUT the tension is exactly the same on both?
the difference in needle size is probably just a tension thing. the person who wrote the pattern wrote down what neele size she used. because people knit at different tensions, you can't rely on needle size.
before you knit a pattern (especially important for things you are going to wear), you have to sit down and knit a swatch and make sure that your gage matches what the pattern lists.
check out this article