Turtleneck, mock neck, crew: what the collar is really for

Full turtleneck

A proper turtleneck is long enough to fold back on itself, which means two layers of knit against the neck. That is why it reads warmer than the same sweater in a crew neck even though the yarn is identical.

It also closes the outfit at the top. Nothing shows above it, so a coat collar sits cleanly and a necklace has nowhere to be. If you find turtlenecks close, look for a looser collar rather than a different neckline.

Mock neck

Half the height, no fold. It gives the vertical line of a turtleneck without the pressure, and it is the one we recommend to anyone who says turtlenecks make them want to pull at their throat all afternoon.

Under a jacket it is the most forgiving of the three, because there is no fold to bunch at the back of the neck.

Crew and round necks

The plain option, and the one that layers under and over everything. A crew neck shows a collarbone, which breaks up the block of colour and stops a heavy knit reading as a wall.

It is also the neckline to pick if you wear a shirt underneath, because there is room for a collar to come out without a fight.

Open and V shapes

These lengthen the line from the chin down, and they take a necklace properly. In knit they are usually the lightest of the four to wear, which makes them the sensible choice for a warm room rather than a cold street.