A prerequisite for beautiful knitting is even tension. Many knitters produce fabric with “rowing out” or gutters, where a space occurs between rows, best seen on the nonpublic side of Stockinette stitch. This occurs generally when knit rows are tighter than purl rows. Exaggerated photos follow.
To check this, hold a Stockinette stitch swatch or knitted item up to a light source to check for gutters between rows. To document that gutters found are from loose purl rows consider adding a lifeline thread as you purl a row or two and eliminating a lifeline for knit rows.
Many possible solutions exist if the purl rows appear looser than the knit rows. These include:
Try to knit looser and purl tighter.
Consider knitting backwards instead of turning the work and purling.
Consider using Portuguese technique with working yarn held taut for the purl rows. The easy Portuguese purl stitch is at the end of this tutorial.
For remaining issues, consider enrolling in the TKGA correspondence course entitled Taming Tension by Binka Schwan. She will have you curing gutters, uneven stitches in ribbing, enlarged purl stitches next to cables and alternating large and small stitches on edges in no time! Register online at https://tkga.org/education/correspondence-courses/#1473286586928-707b24c9-2a64 .
TKGA (The Knitting Guild Association) is the parent body of the MHKP (Master Hand Knitting Program). Even if you have no interest in becoming a TKGA Master Knitter, TKGA an outstanding organization. TKGA’s digital publication Cast On contains a wealth of information for learning knitting techniques, skill building, finishing techniques, stitch anatomy and coping with knitting disasters (Knitting 911). Happy knitting!