No matter what you want to knit, knitting a gauge swatch is NOT OPTIONAL!
Without knowing gauge:
- How do you know how much yarn you need?
- How are you going to know if the finished item will fit?
- Determine if you are even going to LIKE the resulting fabric
- Try out the chosen stitch pattern, maybe it’s too tedious… learn this BEFORE starting to knit
- Dress the swatch and check for shrinkage, pilling, fading
- Save time by knowing AHEAD if the yarn will knit easily