The rib stitch is a versatile stitch that creates a nice stretch to your handmade garments. It is often used in hat brims (sometimes the whole hat), cuffs, waistbands and other specialized uses. To create the rib stitch, we alternate knit and purl stitches in the working row or round and follow the same stitch on the next row(s) or round(s) until we achieve the desired height of the rib stitch.
How to achieve clean stripes when using two or more colors
As much as I love using neutral colors in my knitting, I love using colorful yarns. I am always excited to combine colors in my work. Stripes are one of my favorites. Doing stripes with the rib stitch, however, gets a little more interesting. Let us take a closer look.
Here is a swatch sample of a 2×2-rib stitch, which means the pattern uses knit two purl two or K2, p2. It looks like this when not stretched.
In the photos below, the middle line shows how I knitted the top and bottom parts in two different ways. On the top half, when switching colors, I knit the first row instead of following the rib stitches (knit if it is a knit stitch or purl if it is a purl stitch on the bottom row). However, on the bottom half of the photos, I followed the stitch below. Let us stretch this swatch and look closely.
Figure A – Front of the swatch 
Figure B – Back of the swatch
Figure A – Front of the swatch:
The upper half of the photo shows clean stripes while on the bottom half, notice that the two colors clash a little along the lines.
Figure B – Back of the swatch:
Since I knitted the first row of the color switches, the back shows the purl stitches created which are the visible lines on the upper half of the photo. The bottom half also shows how the two colors clash a little along the lines.
As a conclusion, if both sides of the piece will show (a perfect example would be a scarf), my personal choice would be to follow the rib stitch pattern shown on the bottom half of the photos. It will not have clean stripes but since the elasticity of the ribbing stitch allows to hide the clashing lines, I would prefer that rather than the visible lines on the back (as shown on the top of Figure B).
For something such as a hat, I think the better choice would be the cleaner stripes. Hats when worn will be stretched so the clear lines would look nicer. The wrong side of the work will show the visible lines from the knit row but it would not matter because it will not be seen.
I hope you find this tip useful. Happy knitting!
Shelah Knits 