One of the first steps in the transition from pattern to improv is learning how to alter a pattern--specifically, how to alter the pattern stitch or type of yarn. In other words, learning how to take a basic pattern and adapt it to other gauges.
Your gauge is how many stitches and rows you have per inch (or 10 centimeters). Those numbers (which are used in the pattern to decide how many stitches you start and end with and when and where you increase or decrease) depend on a wide variety of factors:
- Pattern stitch
- Needle/Hook size
- Personality and stress level of the knitter/crocheter
- And sometimes even the material the hook or needle is made of!
- Find the gauge information in the pattern you want to use. I'd recommend learning how to do this with a basic pattern--no fancy textures or shapes. As an example, we'll pretend that the pattern's gauge is 5 stitches per inch.
- Make a swatch of the yarn and stitch you want to use and find your gauge. Again, as an example, we'll say your gauge is 4 stitches per inch.
- Calculate how many inches across the starting row will be when worked according to the written pattern. For example, if you start with 100 stitches at 5 stitches per inch, then the starting measurement is 20 inches (100/5=20)
- Multiply the number of inches in the starting row by the stitch gauge you want to use. In this case, that would be 20x4=80. Your starting number of stitches is going to be somewhere around 80 (you may have to add a few stitches for it to work with your pattern stitch).
- If your pattern has multiple sizes, look for a size that starts with the number of stitches you want. If so, you can follow instructions for that other size. If not, you will have to proceed according to measurements (which you can calculate as you go).
In general, row gauge is less important than stitch gauge. Usually shaping will occur at regular intervals or when the piece measures a specific length, meaning that you can account for differences in row gauge without as much math as stitch gauge. For example, if a pattern tells you to decrease every third row and calls for a row gauge of 6 rows per inch, you know that you need to decrease every half inch.
Whether you are trying to account for a personal difference in gauge that you can't overcome or trying to follow a pattern in a different yarn or pattern stitch, playing with the numbers is an important part of learning how to participate in the design process.