Scissors can be defined as hand implements that use two blades for cutting materials such as paper, cloth, thread, food, hair, etc. The cutting action is created by the shearing motion of the two blades moving against each other, such that the cut moves horizontally while the fingers and thumb of the hand move vertically.
The earliest devices that can be loosely described as scissors were probably made in Egypt in around 1500 BCE. These comprised a single piece of bronze metal formed into a U shape, with the ends of the U sharpened into blades and the curve acting as a spring so that the blades moved apart on release after each cut. However, it would appear that the blades were not designed to cross, which would not have made them particularly efficient.
Cross-bladed scissors were invented in about 100 AD by the Romans, although the pattern followed the Egyptian design, thus resembling the shears used by more recent sheep-shearers and gardeners. Incidentally, the difference between scissors and shears is basically one of size; scissors with blades longer than 15cm are generally referred to as shears. The Romans used iron, which was less brittle than bronze.
The invention of modern scissors, using a central pivot to join the two blades, each of which therefore forms a lever of the first class, appears to have been made at some time before the 6th century, when they were described, by Isidore of Seville, as tools used by barbers. Indeed, there is some evidence that the Romans themselves made this development.
We know that during the Romanesque period, from around 1000 to 1300, scissor-makers were held in high esteem, with craft guilds being formed. The development of other trades and crafts, such as those of dressmaking and calligraphy, led to greater demand for high-quality scissors that would produce clean cuts of cloth and paper.
The name of Leonardo da Vinci is sometimes associated with the invention of scissors although, as we have seen, by his day modern-style scissors were in fairly common use. His contribution, as with several other technologies, may have been to make improvements to what already existed, and thus increased their popularity, but this is one invention for which he cannot take the credit!
A major development came in 1761, when Robert Hinchliffe of Sheffield began to use cast steel to make scissors, which could therefore be made to be highly durable and efficient. He set himself up in London as a manufacturer and purveyor of high-grade scissors.
There have been many developments in the design of scissors in more recent years. For example, there are now scissors for left-handed use, in which the blades are reversed so that a left-hander can see the line of the cut as it is being made, and the handles are molded so as to be comfortable to the left hand. There are specialist tools for surgeons, "pinking shears" for dressmakers and tailors (to produce a zigzag cut in cloth that will not fray easily), safety scissors for children, and even bolt-cutter shears for heavy-duty use, in which the pivot point is placed as close to the blades as possible, to provide greater leverage.
In an age of technology when so many of our tools are power-driven and computer-controlled, it is interesting to note that the humble scissors still have a role to play, in a form that has changed little over thousands of years.