I’m about to start a new project. For the gauge it says…
18 sts and 24 rows = 4" in 2x2 rib on larger needles
So after the 4" part I’m confused. This is a hat and will be my first cable project.
I guess my question is, what stitch should I be using for this gauge and what does the “…in 2x2 rib…” part mean?
TIA! 
Howdy!
2x2 rib is ribbing done by knitting 2 then purling 2 stitches (then on the reverse side you do the opposite) and that’s how you get that ribbed effect like you see on the cuffs of sweaters, hats, etc.
You get “guage” by knitting a swatch slightly larger than 4 inches using the recommended needle size… you then get a measuring tape or a knitter’s guage ruler and count how many rows up and down and how many stitches across you get per inch or per 4 inches. Then, if you count that you have more or less than what the ball of yarn recommends, you adjust your needle size, and sometimes your tension. I believe most people swatch in stockinette but you may want to refer to your pattern, some patterns say to swatch a section of the pattern stitch (in rib, garter, seed, whichever) to more accurately determine your guage for that particular design.
Hope that helps!
Thanks! That does help. Well that’s all my pattern say’s about the gauge so I that means I should knit the 2x2 rib for the gauge.