Punjab PSEB Matric Mechanical Drawing and Painting key terms

A flat rectangular wooden or plastic surface with a smooth working edge, used to support drawing paper and to guide a T-square along its straight edge.

A drafting tool with a long straight blade fixed at right angles to a short stock; the stock slides along the board edge to draw horizontal parallel lines.

A triangular instrument with angles of 45-45-90 or 30-60-90 degrees, used with a T-square to draw lines at fixed angles such as 30, 45, 60 and 90 degrees.

A semicircular graduated instrument marked in degrees from 0 to 180, used to measure and set off angles that cannot be obtained with set squares alone.

A V-shaped instrument with two legs hinged at the top, one holding a needle point and the other a lead or pen, used to draw circles and arcs of a chosen radius.

A drafting instrument with two sharp needle points hinged together, used to transfer measurements from a scale to the drawing and to divide lines into equal parts.

A thin irregular template made of wood or plastic whose curved edges are used to draw smooth free curves through plotted points that cannot be drawn with a compass.

The paper or card on which the drawing is made; standard sizes such as A0 to A4 are used, and the sheet is fixed to the board with tape or clips before work begins.

A thick continuous line drawn a fixed distance inside the edges of the drawing sheet, enclosing the drawing space and separating it from the title block and margin.

A ruled panel, usually at the bottom right of the sheet, giving the drawing title, scale, sheet number, date, and the name of the draughtsman and institution.

A style of freehand capital lettering in which every letter is formed with one continuous stroke of uniform width, written with the aid of guide lines.

A light horizontal pair of lines that fixes the top and bottom height of letters, with an optional middle line for the waist of capitals such as E and H.

The vertical size of capital letters measured between the top and base guide lines, usually chosen in a standard series such as 3, 5, 7, 10 and 14 millimetres.

A thin continuous line with arrowheads at both ends, drawn parallel to the feature it measures, to show the extent of the measurement being given.

A thin continuous line drawn at right angles to a feature, extending slightly beyond the dimension line, to show the exact points between which the dimension is measured.

The pointed solid tip placed at each end of a dimension line, touching the extension line, to indicate precisely where a measurement begins and ends.

A line of short evenly spaced dashes used to show an edge or outline that is not visible from the viewing direction but is hidden by the solid material in front.

A thin line of long and short dashes drawn through the axis of a symmetrical object or circle, used to locate its centre and to show axes of symmetry.

A method of representing an object by projecting its outlines onto two or more mutually perpendicular planes using parallel projectors perpendicular to those planes, giving true shape views.

A projection convention in which the object is imagined between the observer and the plane, so the top view is placed below the front view and the left view to its right.

The principal orthographic view showing the object as seen from the front, chosen to display its most characteristic shape and usually drawn first in the layout.

The orthographic view obtained by looking at the object from directly above, projected onto a horizontal plane and placed in line with the front view.

An imaginary straight line drawn from a point on the object to the plane of projection, used to locate the corresponding point of the view on that plane.

An imaginary flat surface, horizontal or vertical, onto which the outlines of an object are projected to produce an orthographic view; the two principal planes are perpendicular to each other.

A view in which the object is imagined cut by a cutting plane and the part in front removed, so that interior features are shown as solid outlines with hatching on cut surfaces.

An imaginary plane along which an object is imagined to be sawn for a sectional view; its trace is shown by a chain line with thick ends and arrows giving the viewing direction.

Thin equally spaced parallel lines drawn at about 45 degrees across the cut surfaces of a sectional view to distinguish solid material from open space.

A pictorial projection in which the three axes are equally inclined at 120 degrees to one another and all lengths along them are drawn to the same reduced scale.

A construction using a line at 45 degrees and a line at 30 degrees to obtain the reduced lengths used in true isometric projection, about 0.816 times the actual length.

A pictorial projection in which the front face of the object is drawn true shape and size, while receding edges are drawn parallel to each other at a chosen angle, usually 45 degrees.

A form of oblique projection in which receding edges are drawn full scale, giving a deep but somewhat distorted appearance compared with cabinet projection.

The true shape of the surface of a solid laid out flat on a plane, produced by unfolding its faces so that a model can be cut and folded from sheet material.

A method of developing surfaces of prisms and cylinders in which a series of parallel lines representing edges or generators are projected and spaced out along a stretch-out line.

A method of developing surfaces of pyramids and cones in which generators are swung about the apex to lie in one plane, giving a fan of triangles or sectors.

The line along which two surfaces meet or cut each other, found by locating points common to both surfaces and joining them in correct order.

The meeting of two solids so that one passes through the other, producing a line of intersection on the surface that must be drawn accurately in orthographic views.

In perspective drawing, the point on the horizon where parallel receding lines appear to meet; each set of parallel lines has its own vanishing point.

The height of the observer's eye above the ground, which determines the horizon line and therefore how much of the top or bottom of an object is seen.

In perspective and outdoor sketching, the horizontal line where sky and ground appear to meet, lying at the observer's eye level and containing the vanishing points.

The relative size of one part of an object or composition compared with another, judged by comparing lengths and widths with the help of a pencil held at arm's length.

A drawing made by hand without instruments, using light construction lines and firm flowing strokes to record the shape and proportions of an object quickly.

A light thin line drawn first to fix the general shape, axes and proportions of a sketch or drawing, later darkened or erased as the final outlines are drawn.

One of the three basic colours, red, yellow and blue, that cannot be obtained by mixing other colours and from which other colours are made by combination.

A colour obtained by mixing two primary colours in equal parts, namely green from yellow and blue, orange from red and yellow, and violet from red and blue.

Either of a pair of colours placed opposite each other on the colour wheel, such as red and green, which contrast strongly and dull each other when mixed.

A circular arrangement of hues in spectral order showing primaries, secondaries and their mixtures, used to select harmonious or contrasting colour schemes.

The name of a colour family, such as red, blue or yellow-green, that distinguishes it from other colours regardless of how light, dark or dull it may be.

The lightness or darkness of a colour or tone, ranging from the lightest tint to the darkest shade, and the chief means of showing form and light in painting.

The purity or strength of a colour, describing how vivid or greyed it appears; adding grey or a complementary colour lowers saturation without changing hue.

A thin even layer of water-based paint applied with a brush and allowed to dry flat, used in watercolour work to lay broad areas of transparent colour.

A watercolour technique in which fresh paint is applied onto a still-damp surface, so the colours spread and blend softly with feathered edges.

Applying a thin transparent layer of colour over a dry painted surface so that the underlying colour shows through, used to deepen tone without hiding earlier work.

The arrangement of shapes, tones and colours within the picture space so that the parts relate harmoniously and lead the eye to the main centre of interest.

A guide to composition in which the picture is divided into three equal parts each way and important elements are placed near the intersections of those lines.

The area of a painting that first attracts the viewer's attention, usually made prominent by strong contrast, sharp edges or the brightest and most saturated colour.

A painting or drawing of inanimate objects such as fruit, bottles and drapery arranged on a table, studied for shape, texture, light and shadow.

The use of strong contrasts between light and dark in a picture to give objects a sense of solid volume and to create dramatic atmosphere.

The dark shape thrown by an object onto a surface when it blocks the light, whose direction and length depend on the position of the light source.

Direct observation and drawing or painting of natural forms such as leaves, flowers, trees and rocks, recording their structure, colour and growth pattern accurately.