IAE 227a: Technical Drawing
Module 2
2nd Semester, S.Y. 2022-2023
INSTRUCTOR: MR. RHALDEN JOHN A. ARANSADO
Email: rhaldenjohn.aransado@ustp.edu.ph
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Contact No.: 09502254925 SMART
Introduction
If you examine any drawing, you will find that it contains certain printed material in the form of words
and numerals. This information indicates the size of the part drawn and its relationship to other parts. It
also shows the accuracy required to make the object, the material to be used, the name of the person
making the drawing and the date when the drawing was complete. The process of putting this data on a
drawing is known as lettering. Since lettering is an essential part of a drawing, the letters and numerals
must be easy to read. Not only should be easy to read, but they must have a pleasing appearance. Every
draftsman must learn to letter rapidly and neatly. Poor lettering can mark a good drawing.
Intended Learning Outcomes
The students are expected to:
Topic :
tell the importance of lettering.
enumerate the classification of letter styles.
construct the different proportion of letters.
 discuss the characteristics of a good lettering.



LETTERING
Proper lettering in technical drawing is important and cannot be underestimated. The right execution
of the standard literal and numeral interpretations of technical ideas will result in a neat, orderly and
accurate drawing. Any person can learn to letter if a persistent and intelligent effort is made. While it is true
that “practice makes perfect”, it must be a accompanied by continuous effort to improve.
Lettering is a freehand drawing and not writing. Therefore, the basic fundamental strokes and
direction for freehand drawing are basic to lettering. Good lettering is always accompanied by conscious
effort.
The Four Group of Letters
1. Gothic Letters. They are the most simple and readable among the
four group of letters. It has a uniform stem. It should be applied
only for poster and advertisement purposes.
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Aa Bb Cc Dd Ee Ff Gg Hh Ii Jj Kk Ll Mm Nn Oo
Pp Qq Rr Ss Tt Uu Vv Ww Xx Yy
Two forms of gothic letters:
a. Commercial Gothic. It is printed with heavy stem. It is
used for advertisement purposes only.
b. Single Stroke. It is printed with thin stem. It is used for
engineering drawing purposes.
2. Roman
Letters. The thickness of these letters is not uniform. they
have pointed stem which is called “serif”. They must be used for
books, magazine, newspapers, and text matters.
Aa Bb Cc Dd Ee Ff Gg Hh Ii Jj Kk Ll Mm Nn Oo Pp
Qq Rr Ss Tt Uu Vv Ww Xx Yy
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The Three Classics of Roman Letters:
a. Old Roman Letters. They are printed by means of
layout form using the flexible lettering pen. The
thickness of the thin stem must be ½ from the
thickness of the heavy stem.
b. Modern Roman Letters. They are printed in single
stroke using the speedball pen.
c. Modified Roman. Similar to Modern Roman, they are
printed in single stroke using the speedball pen.
However, this style must be printed in the absence of
serif.
3. Spanish Script. It is considered as artistic letters. It is purposely
used for certificates, diplomas, citations, greetings and invitation
cards.
4.
Text or Old English. This style is the most artistic among the four
groups of letter. Similar to Spanish script, it is also used for
certificates, diplomas, citations, greetings and invitation cards.
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The Rule of Stability of letters
This refers to the standard rules to be considered in printing the
letters particularly on the following:
1. Upper Case letters. They are letters which are printed in capital form.
Three guidelines are cap line, waist line, and base line.
Example:
cap line
ABCDEFG
waist
line base line
2. Lower Case Letters. These are the letters which are printed in small
letters printed with the use of four guidelines such as cap line, waist
line, base line, and dropped line.
Example:
cap line
abcdfgy
waist line
base line
dropped
line
The General Proportion of Letters
1. Compressed or Condensed. This particular proportion should be
applied only when the space is limited. The letters are printed with
closer distance and its width is narrower than the normal size.
Example:
COMPRESSED
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2. Extended. This proportion is applied when there is a more space.
The width of the letter is wider than the height.
Example:
3. Normal. This proportion is applied when there is normal space. The
letter is printed in the normal size.
Example:
NORMAL
The Two Proportion of Thickness
1. Boldface. This refers to the letters which are printed with heavy
stem. Example:
BOLDFACE
2. Lightface. This refers to the letters which are printed with thin
stem. Example:
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Below are the suggested lettering tools and instruments and their uses:
1.
used in writing different various styles
Speed Ball
-
of
letters
2.
Lettering Brush -
used for sign painting
3.
Felt Point Pen
used for sign painting
4.
Letter Template -
used as guide for letter transfer
5.
Letter Transfer -
used to direct letter transfer
6.
Pencil
-
used for lettering and sketching
7.
Technical Pen
-
used for Gothic letters
8.
Leroy Lettering Pen -used for engineering and architectural
-
lettering
Order of Strokes in Lettering
The first letters that should be studied are I, L, T, F, E, H. These
letters are the easiest to draw because the basic strokes are vertical and
horizontal. You should practice making these letters according to the
models.
The next group P, R, B, U and J requires close study because of the
introduction of the curved line aside from the three already given.
The last group of letters is C, G, O, Q, D and S which are based on
the
circle.
The M and W must be printed wider than the other letters. It is
suggested therefore that its width should be greater than the other
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letters by 25 percent. The letter I is the thinnest letter.
Making Numerals
All mechanical drawings involve the use of numerals, hence, they
should be studied closely. Notice that in the figures below are all 6 units
and 5 units wide except 1. All figures are composed of the essential
strokes found in the letters which are straight and curved. See Figure 1.1
Single stroke vertical upper case letters and numerals
Figure 1.1
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Single stroke vertical lower case letters
Figure 1.2
Single stroke inclined upper case lower case letters and numerals
Figure 1.3
Single stroke inclined lower case letters
Figure 1.4