Art materials - Graphics
Graphics is a very broad term these days and can include works done by hand, by printing as well as works on screen. There are new developments in these areas, happening all the time. It is impossible to create a comprehensive list but here we will attempt to cover the more common terms you might encounter.
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Pronounced 'gwarsh', this is a paint that is transparent. Guache was originally used in design drawings, e.g architectural plans, where the artist wants to give the drawing more emphasise. It is a popular addition to pen and ink works. The waterproof drawing ink shows through the transparent colour.
Tempera is a coarse opaque paint originally made from egg yolk and pigment. Usually available in a powder, it is mixed with water. Until the development of acrylics, this was the most common paint used in schools.
GSM or gsm
This is an abbreviation for grams per square metre and refers to the weight of paper, which usually equates it's thickness. A typical writing paper or the paper used in a standard computer printer is around 85gsm. Artists paper is generally thicker and is typiclly 110gsm, to resist buckling.
Ink and Drawing Ink
Inks differ. Drawing ink is usually waterproof when dry, whereas writing ink is not and will blot and run if it gets wet, Chinese and Japanese painting uses ink disolved from a solid stick and is not waterproof when dry. Drawing inks are available in a variety of colours. There are also heat set inks for fabric printing. Once ironed this ink becomed insoluble. Printing inks come in two forms, oil based (thin with turpentine) or water based. The oil based inks usually appear more vivid.
In this Japanese brush set the ink is the ornately decorated stick at the top right of the red velvet case.
A printing technique where a flat surface is scratched or engraved. The suface is then inked and wiped off, leaving ink in the hollows in the plate which is then used to print. The name comes from Latin meaning 'To scratch'. This method results in an image composed of soft fine lines, Intaglio can also refer to any technique where an image is formed by scratching away a contrasting surface.
Relief and relief printing
Relief refers to a raised surface. In sculpture the subject is separated from the background by raising it above the background - the subject is said to be in relief. In printing the unwanted area is hollowed out so only the raised surface is inked and printed. This is called relief printing. This is the most common form of printing. Woodcuts, linocuts, offset, lithograph and copperplate are all examples of relief printing.
H, HB, B 2B - Pencil grades
Pencil lead is not made of lead at all. It is made from a mixture of carbon in the form of graphite and clay. A lead composed of more clay than graphite will be hard (H) whereas a lead composed of a higher portion of graphite will be softer, more graphite will wear off,drawig a blacker line (B). Thus a HB lead is equal portions and is a moderately dark lead favoured for general writing and drawing. The B series pencils are favoured for sketching.
These are coloured pencils made with leads of water colour paint. When an area is coloured and washed with a wet brush the colour intensifies and turns into a water colour.
A floral picture drawn with Aquarelle pencils. With limited practice you can get some astounding results and it is quite a thrill to watch the picture transform. If you think water colours are too hard, try these.
Pastel and oil pastel
Favoured for quickly capturing an image by hand, pastels are a popular medium with artists. The down side is they are difficult to preserve. They are easily smudged and being a powder, if placed behind glass, they need to be spaced away from the glass. Oil pastels are not quite as easy to smudge. With a brush and turps, they can be worked to form a wash.
These are used for painting on fabrics. They handle similar to oil paints but are cured with heat, usually by ironing. Applied by brush or screen printed, they can be thinned with turpentine.
This is a form of printing favoured for its ability to render both fine detail as well as soft graduations. An image is drawn onto stone. The exposed surfaces are etched and the result is relief printed. The name is derived from the Greek words, litho for stone and graphos for picture.
Woodcut or Woodblock
This was a popular form of printing in the Middle Ages. An image in reverse is cut into the end grain of a block wood so that it is in relief. This is inked and printed by laying a sheet of paper over the woodblock and pressing it to transfer the ink. It was much quicker and didn't require special materials like lithography or copperplate printing. The print is characterised by a bold contrast with limited detail.
Engraving or Copperplate
This type of printing was far more time consuming than woodblock. However it yielded fine detail that was difficult to copy unless you had the original plate. For this reason, until the computer age, this was the method used to print documents and currency notes. A reverse image was carved into a sheet of metal using specially made fine chisels called gravures. Engravers were highly respected trades people until the computer age. Today this trade is still sought after in manufacturing jewellery. Copper was the favoured metal because it was hard enough to produce thousands of impressions but was able to be carved by a skilled engraver. Below is a section of the above engraving showing the gravure marks and how they vary in depth to make the graduation in tones.
Offset Printing, Computer printers
This printing method relies of semi opaque inks applied in several layers, each of a single primary colour, beginning with the lightest colours first. A separate printing plate is required for each colour. A small amount of the under layer is left showing through to create pure colours. Because the inks are not fully opaque, primary colours overlaid over each other appear to mix forming secondary colours. For example blue over yellow will become green. Most commercial printing is done this way today. Computer printers use this same technique except they use dots. When all three primary colours appear in the same area, they form black. Inkjet printers squirt a tiny dot of each coloured ink, Laser printers charge a drum with static electricity which attracts a dust of plastic which is then heat set onto the paper.The offset process is used in both types of printer.
This is the art form of lettering. In western culture we tend to imagine ancient manuscripts, however this art form is very much alive and well in Islamic countries, where it is used with passages from the Quran. In Japan and China it is a highly respected art form.
A quote from the Quran - calligraphy thrives in the Middle East where religous imagery of people is not allowed, as an art form and in Asia which has always regarded writing as an art form."
This is a technical form of drawing used to convey dimensions. Used in house plans and engineering drawings it shows an object viewed from different angles exercised with standardised symbols and line formats to show hidden detail, lines of symmetry and distinguish between dimensional lines and the boundaries of the subject.
This method of technical drawing displays the subject in a 3-D view turned at 30 degrees to the viewer however it does not show perspective. Circles become ovals when drawn in isometric. This method is favoured when a more realistic view is required, for example identifying a part in the auto-industry, where parts are shown in isometric and an exploded view as shon below.
This is the visual cue that adds depth perception to a 2-D rendition. Visual trickery, like objects becoming smaller as they move into the distance and near objects obscuring far ones give the illusion of depth and make a flat picture appear three dimensional.
By shrinking the buildings as we near the vanishing points 1 and 2, we give the illusion of distance and make our drawing more realistic.
A screen of fine meshed fabric (similar to nylon stocking material) is set in a frame. Areas of the screen that are not to be printed, are blocked out either with some kind of film or alternatively painted, to seal the mesh. The mesh screen is then placed on top of the work and ink is wiped over the screen. The areas not sealed will print with ink.
This technigue is popular with circuit board manufacturers. They print their design onto a copper foil coated sheet with insoluble inks. The printed board is then dipped in an etching solution and the uncoated copper areas are eaten away, leaving copper tracks. Components are then soldered to these tracks and a coat of lacquer is sprayed over the copper tracks to prevent corrosion.
Rendering and Wireframe
This is the term used for turning drawings or sketches into lifelike forms. An outer surface is added to a line drawing. To get a convincing surface the drawing needs many more lines to describe the surface, becoming what is called a wire or wireframe. The rendering software will treat these as tiles and create a surface adding colour, texture and shading to complete the 3-D illusion.
A 3-D rendering of a sphere, treated three different ways, as a smooth solid, a metallic and as glass orb."
Matte, chroma compositing and blue screen
Literally matte means a non glossy surface but it has another meaning in graphics. It refers to the backgound art in a film production, which has to be rendered convincingly to fool the audience. It is usually very large and painted so it has no gloss finish to give away the fact it is only a picture. It is often painted on several wall sized panels joined seamlessly. In the early days of computer cinema graphics, the actors would be filmed against a blue screen and the computer would overlay this over the matte and digitally remove the blue background from the film layer with the actors. Today computers can remove any background so the backdrop doesn't need to be blue but the term 'bluescreen' still persists however is gradually being replaced by the more technical term "chroma compositing". Mattes are also used for video game development and still photography today.
In motion picture production, the foley artists are the unsung heroes who add the sounds that make the scenes more convincing. It might be the swish of fabric from the actress' ball gown that, although you might not actually register it, emphasised the luxuriousness of the gown. It could be the sound of someone walking away off screen, horses trotting, breaking glass, a creaking door or wind noise. Often the microphones do not pick up a convincing rendition of everyday sounds, like wind, waves and breaking glass. The mark of a good foley artist is their work always goes unnoticed but the audience feels the scene is realistic. A common example is where a conversation is heard on a night club dance floor. Have you ever tried to talk on a dance floor? Often these scenes are recorded with no music at all. The music and babble is added later by the foley artists.