Swatches really answer two questions. “Do you want the item to fit?” and
Swatches really answer two questions. "Do you want the item to fit?" and "Do you like the fabric that is created?"
In the swatch shown, you should be able to count eight stitches for two inches horizontally and eleven rows vertically for two inches . Thus my stitch gauge is 4 stitches per inch, and 5 1/2 rows per inch. The bigger the swatch, the more accuate thegauge becomes.
There are many knitters that just knit the back to the underarm and use that for the gauge for the rest of the garment. They will adjust the side seams forward or back on the front pieces to account for any discrepancy!
Creating the fabric comes first. The pattern designer has done swatches to determine the best fabric for the pattern. That is how the needle and yarn recommendations are determined.
Thus knitters only worry have to worry about getting the gauge so that the garment fits. If your swatch matches the row and stitch gauge stated in the pattern, then the finished garment should be the size stated in the pattern.
Notice the use of "Should be". I always check the math for the finished chest measurement (or any part of the garment where fit is critical as in sleeve length).
First it is important to note how the pattern wants you to knit the swatch. Sometimes they will tell you to knit in stockinette stitch and sometimes the instruction is to work in pattern. Keep in mind that the larger the swatch that is knit, the more accurate the gauge becomes.
If your swatch is the specified size (row and stitch count), then you can start on the garment.
While I knit tighter than most people, I frequently do manage to obtain the gauge on the recommended needles. The lace shown to the right was an exception. Using the recommended needles and pattern, my stockinette square resulted in a three inch square. Because the gauge was so far off, I chose to go up two needle sizes.
With 471 cast on stitches, I worried until row 23 was completed and I could check my knitting. As the ruler indicates, my needle selection was correct. While a shawl can be any size, I really wanted the drape that would result from an accuarte gauge.
Shown is a section of a lace shawl that I am knitting. Pattern is Titania's Shawl from Summer 2017 of Interweave Knits.