Is cotton yarn to heavy to make a sweater?
It all depends. Typically, cotton is lighter than wool, but again all depends. Check these awesome resources:
Learn to Knit: Making a Gauge Swatch by Lion Brand
How do I substitute one yarn for another? by Lion Brand
This text was written by Wendy Chatley Green in 1995.
In truth, the type of project determines the type of yarn. Ragg yarn, a thick yarn made from one ply of shoddy and two plies of wool, makes a great warm sock but a terrible lace tablecloth. Cobweb Shetland makes a flimsy Aran sweater but is perfect for an heirloom shawl. Wool will drive an allergic person to distraction but some people hate the feel of acrylics. Some natural fibers will felt and become weatherproof; others are poor insulation.
Whatever the yarn is worked into is fabric, whether it is woven, knit, crocheted or processed by another method.
The number of plies in yarn has nothing to do with thickness. A yarn made of four firm plies may be thinner than one made of two loose ones. That having been said, yarn strength and evenness depends on the number of plies. Yarn is usually plied (the act of twisting the twisted strand together) in the opposite direction of the individual strands. This corrects the tendency of the yarn to slant as it is worked. A sweater made from a firm, multi-ply yarn knit with a small gauge might survive generations of wearers.
Unplied yarn is a hunk of wool that has been stretched out a little. Roving, a fluffy bulky yarn with no twist, is an example of this. Sweaters made of roving are fragile and tend to pill.
Extra-fine yarns are used in lace-knitting. Some of these are spun as thin as a human hair. A shawl made of this wool might weigh only two ounces but contain 6,000 yards of yarn.
"Worsted" is the term used for what most people think of as sweater yarn but worsted is actually the term for a yarn whose fibers were combed before spinning. This sweater name is more properly called 'double-knitting' in England and 'Germantown' in America.
Heavy yarns are thick ones meant for large needles. Bulky and chunky are synonyms.
Shoddy is yarn or fabric made from scraps; obviously, it has been worked beforehand. Since it does not wear well, its name is used to describe anything poorly made.
Felt is what happens when wool shrinks and mats together; the action is usually irreversible.
Pills are little matted balls that form on sweaters. They happen as the soft yarn rubs against itself and the fibers tangle.
Knit-alongs are yarns knit with the main yarn in a fabric. They do not affect the gauge of the pattern but add strength, color or pizzazz.
Gauge is not a fiber term. It is the number of stitches per inch the yarn gives when knitted. Although the size of the yarn is a factor, needle or hook size and the tightness with which the yarn is worked also determine gauge. [Editor's note: "gauge" is known as tension in the UK.]
Hand is how a yarn feels.
There was a great discusson about this on the Sewaholic blog the other week. Tasia made a cotton sweater but the weight was too much and the end of the day her sweater was all stetched out. I'm linking it here because there was some really good advice about how to avoid issues when knitting with cotton.