One of the benefits of knitting your own garments is modifying patterns to suit your unique needs and personal preferences. Although knitting patterns are written with a specific finished outcome in mind, knitters can take liberties with the pattern to produce a sweater that appeals to them. Changing the neckline of a garment dramatically modifies the appearance. A crew-neck, such as you would find on a T-shirt, is a simple and understated neckline. Roll-necks, also called turtlenecks or polo necks, are more dramatic. Converting a crew neck sweater pattern to a roll neck sweater pattern is a simple change that even novice knitters can accomplish.
Knit your sweater until you reach the neckline portion of the pattern.
Complete the neckline decreases dictated by the pattern. The number of stitches required for a roll-neck sweater does not change from the number required for a crew-neck sweater.
Continue knitting past the point where the pattern tells you to stop. A roll-neck sweater is longer than crew-neck sweater.
Knit as many rows as is necessary to create a collar that is the length of your neck with a little extra left to fold over, up to double the length of your neck. The amount you need to knit varies from knitter to knitter depending upon the gauge or tension of your knitting.
Bind off the sweater neck as directed by the pattern. Some patterns require you to use a specific bind-off to ensure that the sweater opening is stretchy enough to fit over your head.
Cast on the required number of stitches as dictated by your pattern. Use the cast-on method dictated by the pattern. Some patterns require the use of a stretchy cast-on to ensure the sweater fits over your head.
Knit in the stitch pattern dictated by the pattern.
Continue knitting until the neckline is equal to the length of your neck with a little extra to fold over, up to double the length of your neck.
Start the neckline increases as dictated by the pattern. Neckline increases must occur in order to transition from the neck to the body of the sweater. The extra length needed for a roll-neck sweater does not require adding extra width at the top of the collar.
Knit the rest of the sweater as described by your pattern.
There is no significant planning or design alteration needed to convert a crew-neck sweater pattern to a roll-neck sweater pattern. A roll-neck sweater collar is simply an extended or overgrown crew-neck. If you make a roll-neck too long on a bottom-up sweater, you can easily unpick the extra rows of knitting and bind off earlier. Sweaters knit from the top-down are not easily undone to correct mistakes in neck length.