Slate (writing)
Encyclopedia
A writing slate is a piece of flat material used as a medium for writing
Writing
Writing is the representation of language in a textual medium through the use of a set of signs or symbols . It is distinguished from illustration, such as cave drawing and painting, and non-symbolic preservation of language via non-textual media, such as magnetic tape audio.Writing most likely...

.

In the 19th century, writing slates were made of slate
Slate
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. The result is a foliated rock in which the foliation may not correspond to the original sedimentary layering...

, which is more durable than paper
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....

 and was cheap at the time when paper was expensive. It was used to allow children to practice writing
Writing
Writing is the representation of language in a textual medium through the use of a set of signs or symbols . It is distinguished from illustration, such as cave drawing and painting, and non-symbolic preservation of language via non-textual media, such as magnetic tape audio.Writing most likely...

. Thin slabs of slate, typically three inches by five (roughly 9 × 12 cm), were also bound into "slate books" for adult use in workplaces.

Slates can be written on using a slate pencil. This is a rod made of soft slate, soapstone
Soapstone
Soapstone is a metamorphic rock, a talc-schist. It is largely composed of the mineral talc and is thus rich in magnesium. It is produced by dynamothermal metamorphism and metasomatism, which occurs in the areas where tectonic plates are subducted, changing rocks by heat and pressure, with influx...

, or pressed clay
Clay
Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...

, which makes a thin white line on the slate. Chalk can also be used. The writing can be wiped off with a soft cloth.

Writing slates, although not made of the rock, are still used:
  • Scuba divers
    Scuba diving
    Scuba diving is a form of underwater diving in which a diver uses a scuba set to breathe underwater....

     carry plastic
    Plastic
    A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...

     slates and pencil
    Pencil
    A pencil is a writing implement or art medium usually constructed of a narrow, solid pigment core inside a protective casing. The case prevents the core from breaking, and also from marking the user’s hand during use....

    s to communicate with other divers
    Underwater diving
    Underwater diving is the practice of going underwater, either with breathing apparatus or by breath-holding .Recreational diving is a popular activity...

    , to record facts underwater
    Underwater
    Underwater is a term describing the realm below the surface of water where the water exists in a natural feature such as an ocean, sea, lake, pond, or river. Three quarters of the planet Earth is covered by water...

     or read pre-dive plans.
  • Proprietary writing slates which protect young children and their clothes from the damage and discolouration potentially caused by paint
    Paint
    Paint is any liquid, liquefiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film. One may also consider the digital mimicry thereof...

    , pencil
    Pencil
    A pencil is a writing implement or art medium usually constructed of a narrow, solid pigment core inside a protective casing. The case prevents the core from breaking, and also from marking the user’s hand during use....

    s and pen
    Pen
    A pen is a device used to apply ink to a surface, usually paper, for writing or drawing. Historically, reed pens, quill pens, and dip pens were used, with a nib of some sort to be dipped in the ink. Ruling pens allow precise adjustment of line width, and still find a few specialized uses, but...

    s are used as toy
    Toy
    A toy is any object that can be used for play. Toys are associated commonly with children and pets. Playing with toys is often thought to be an enjoyable means of training the young for life in human society. Different materials are used to make toys enjoyable and cuddly to both young and old...

    s or educational items.

See also

  • Chalkboard
    Chalkboard
    A chalkboard or blackboard is a reusable writing surface on which text or drawings are made with sticks of calcium sulfate or calcium carbonate, known, when used for this purpose, as chalk. Chalkboards were originally made of smooth, thin sheets of black or dark grey slate stone...

  • Pen computing
    Pen computing
    Pen computing refers to a computer user-interface using a pen and tablet, rather than devices such as a keyboard, joysticks or a mouse....

  • Slate (disambiguation)#Electronic devices
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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