Lettering in Engineering Drawing Lettering is used to provide easy to read and understand information to supplement a drawing in the form of notes and annotations. Thus, it must be written with: Legibility – shape & space between letters and words. Uniformity – size & line thickness. Lettering is an essential element in both traditional drawing and Computer Aided Design (CAD) drawing
Types of Lettering The two types of lettering are: 1. Double Stroke Lettering . 2. Single Stroke Lettering. 1. Double Stroke Lettering In Double Stroke Lettering the line width is greater than that of Single Stroke Lettering. Double Stroke Lettering is further divided into: Double Stroke Vertical Gothic Lettering. Double Stroke Inclined Gothic Lettering. A stencil is mostly used when hand drawing double stroked letters.
2. Single Stroke Lettering Thickness in single stroke lettering is obtained by a single stroke of pencil or ink pen. It is further divided into: Single Stroke Vertical Gothic Lettering. Single Stroke Inclined Gothic Lettering. Single stroke vertical letters Single stroke inclined letters
Conventions for Lettering • • • • • • Use all CAPITAL LETTERS. Use even pressure to draw precise, clean lines . Use one stroke per line. Horizontal Stroke are drawn left to right . Vertical Strokes are drawn downward . Curved strokes are drawn top to bottom in one continuous stroke on each side. Use kerning to eliminate excessive space between letters. – [kerning refers to adjusting the space between characters, especially by placing two characters closer together than normal. Kerning makes certain combinations of letters, such as WA, MW, TA, and VA, look better.] •
Conventions for Lettering (cont.) • • • • • • • • Use The Single-stroke, Gothic Style of Lettering . Always Skip A Space Between Rows Of Letters . Always Use Very Light Guide Lines . Fractions Are Lettered Twice The Height Of Normal Letters . Fraction Bars Are Always Drawn Horizontal . Use a Medium (B, HB, F or H) Lead For Normal Lettering. Use a Hard (2H To 4H) Lead For Drawing Guide Lines . Notes should be double spaced .
Application of Lettering Lettering in Engineering Drawings is used in writing Title Blocks which play a crucial role in drawings, they are used to record all of the important information necessary for the working drawings. A HB Pencil is used. What does the Title Block contain? Other uses of lettering include Dimensions and Notes on the engineering drawing.
Placement of text on Engineering Drawings Try and locate the text on the drawings going around.
Guidelines Extremely light horizontal lines that are necessary to regulate the height of letters . In addition, light vertical or inclined guidelines are needed to keep the letters uniformly vertical or inclined. Guidelines are absolutely essential for good lettering . Guidelines are drawn using Hard (2H to 4H) Lead Pencils with light pressure. HB grade conical end pencils are used for lettering . Procedure for Lettering • • • Thin horizontal guide lines are drawn first at a distance ‘h’ apart. Lettering Technique : Horizontal lines of the letters are drawn from left to right . Vertical, inclined and curved lines are drawn from top to bottom. After lettering has been completed, the guidelines are not erased .
Guidelines in Lettering (including Height) b 1 h -(height of capital letters) c 1 -(height of lower-case letters) c 2 -(tail of lower-case letters) c 3 -(stem of lower-case letters) -(spacing between baselines) -(spacing between baselines) Recommended Size (height, h) of Letters/Numerals Main Title 5mm, 7mm, 10mm Sub-Title 3.5mm, 5mm Dimensions, Notes 2.5mm, 3.5mm, 5mm etc. h c 2 c 2 b 2
Guidelines for Lettering • • • • • Drawing numbers, title blocks and letters denoting cutting planes, sections are written in 10mm size . Drawing title is written in 7mm size . Hatching, subtitles, materials, dimensions, notes etc. are written in 3.5 mm size . Space between lines is 3/10 h (height of capital letters) Space between words may be equal to the width of the alphabet M or 3/5 h (height of capital letters). Standard height for CAPITAL Letters and Numerals according to the Bureau of Indian Standards (BIS) is: 1.8, 2.5, 3.5, 5, 6, 10, 14, 20 mm. (Sizes selected based upon size of drawing)
Guidelines for Lettering
Basics of Single Stroking Straight Slanted Horizontal Curved 1 1 2 3 “ I ” letter “ A ” letter 2 3 4 1 5 6 “ B ” letter E xa m p l e s
Order of Strokes Stroking is done based on the slope of each letter and the strokes vary with order and direction.
Various Single Stroking Groups
Stroking for Upper Case Letters & Numerals Straight line letters Curved line letters & N umer a l s
Stroking for Lower Case Letters
Stroking Groups The I-H-T Group The letter I is The Foundation Stroke . The top of T is drawn first to the full width of the square and the stem is started accurately at its mid point. I H T
Stroking Groups The L-E-F Group The L is made in two strokes. The first two strokes of the E are the same for the L, the third or the upper stoke is lightly shorter than the lower and the last stroke is the third as long as the lower. F has the same proportion as E. L E F
Stroking Groups The V-A-K Group V is the same width as A, the A bridge is one third up from the bottom. The second stroke of K strikes stem one third up from the bottom and the third stroke branches from it. V A K
Stroking Groups The M-W Group Are the widest letters. M may be made in consecutive strokes of the two verticals as of N. W is made with two V’s. M W
Stroking Groups The O-Q-C-G Group The O families are made as full circles and made in two strokes with the left side a longer arc than the right. A large size C and G can be made more accurately with an extra stroke at the top. O Q C G The O-Q-C-G Group stroking will be demonstrated on the whiteboard
Stroking Groups The O-Q-C-G Group (cont.)
Stroking Groups The D-U-J Group The top and bottom stokes of D must be horizontal, fail line to observe this is a common fault with beginners U is formed by two parallel strokes to which the bottom stroke be added. J has the same construction as U, with the first stroke omitted. D U J Note:- The bottom stroke in J is drawn once, and not twice as shown in the animation.
Stroking Groups The P-R-B Group The number of stokes depends up on the size of the letter. The middle line of P and R are on centerline of the vertical line. P R B
Stroking Groups The N-Z-X-Y Group The parallel sides of N are generally drawn first. Z is drawn without lifting the pen. Z and X are both started inside the width of the square on top and run to full width on the bottom. N Z X Y
Other Stroking Groups The S-8-3 Group The 0-6-9 Group A perfect 3 should be able to be completed into an 8; An 8 can be made from an S construction. The S is made up of three strokes. The cipher (zero) is narrower than the letter O and made of two strokes. The 6 and 9 have the cipher as their backbone. With their lobes 2/3 the figure’s height.
Other Stroking Groups The 2-5-7-& Group The Fraction Group • • Always made with a horizontal vinculum (a horizontal line used in mathematical notation). The figures are two-thirds the height of the whole numbers , with a clear space above and below the line, making the total height of the fraction nearly twice the cap height (h). The bottom of 2 and top of 5 and 7 should be straight lines. For 2 the reverse curve should cross the center of the space. The ampersand (&) is made of three strokes.
The Fraction Group (Example)
S p a c ing Uniformity in spacing of letters is a matter of equalizing spaces by eye. The background area between letters, not the distance between them, should be approximately equal. Words are spaced well apart, but letters within words should be spaced closely. For either upper case or lower-case lettering, make the spaces between words approximately equal to a capital O. LINES AND LETTERINGS Avoid spacing letters too far apart and words too close together. L I N E S L E T T E R S
Types of Spacing
Space between letters D R AW ING Contour Contour can be denoted as straight , slant and curve . Adjacent contour can be straight-straight : II, IN, IM, IP etc. straight-curve (or curve-straight) : IO, QR etc. 3. straight-slant (or slant-straight) 4. curve-curve 5. slant-curve (or curve-slant) 6. slant-slant 7. The ‘L’ and ‘T’ : IV, IW etc. : OO, OG etc. : VO, WG, VC etc. : VW, VX etc. : LT
Space between letters
Space between letters
Lettering Uniformity Important to produce good drawings. • • • Uniform in style, size, inclination, weight and space. Carelessness might result in mistakes. ENGINEERING DRAWINGS Space between letters Spacing between characters, is normally (2/10)h. Spacing between words, is normally (6/10)h. where h is the cap height.
Examples of Common Mistakes in Lettering Lettering style not uniform Lettering height not uniform Lettering inclination not uniform Lettering thickness not uniform Lettering space not uniform L E t T E r I N G L E T T E R I N G L E T T E R I N G L E T T E R I N G LET T E R ING
In Class EXERCISES: Refer handouts given Thank you…