A pair of scissors is generally not more than 6 inches in length and the two finger loops, called rings or bows, are equal in size. Scissors are designed for lighter cutting tasks. Sewing scissors have one sharp point and one blunt point to prevent snagging and are used for general sewing. They are used for trimming seams, notching, clipping curves, ripping and cutting threads at the sewing machine. Needlepoint scissors have two extra-sharp pointed blades.
A pair of shears is normally 6 inches long or more and the rings are of different sizes; one round, one oval. The smaller of the two is for the thumb, and the larger is to accommodate two or three fingers for better leverage. Shears are suitable for heavier cutting tasks.
Another characteristic of shears is that they are either bent or straight. Bent shears make it easy to cut material on a tabletop, and for this reason are often referred to as dressmaker shears. Straight shears are more suitable for general-purpose use and are usually known as household shears.
Most shears have one sharply pointed blade and one that is semi-rounded. The handles are normally contoured to allow them to fit snugly into the hand during use. The larger the shears, the larger the handles, so it follows that people with larger hands will prefer the larger shears.
