3.3: Lettering Guidance

All text on drawings should be simple and readable. The standard style of lettering is single-stroke Gothic, a text style that does not have serifs or ornaments of any kind. It closely resembles the Helvetica or Arial typeface. Even in the digital age, learning how to letter manually is valuable as engineers often need to document information manually.

One Stroke Lettering:

Single-stroke lettering, also known as one-stroke lettering, is a writing style commonly used in engineering and architectural drawings. It's called "single-stroke" because each part of the letter is drawn with a single stroke of the pencil or pen. This lettering style is characterized by its simplicity, readability, and lack of decorative elements such as serifs. Here's a brief description of how to create single-stroke letters:

Straight Lines

For letters composed of straight lines (like A, E, F, H, I, L, M, N, T, V, W, X, Y, Z), start by drawing the vertical lines from top to bottom in a single stroke. Then, draw the horizontal lines from left to right. For letters like 'A', 'M', 'N', 'V', 'W', 'X', 'Y', 'Z', which have diagonal lines, draw these lines in a single stroke from the top to bottom.

Curved Lines

For letters with curves (like B, C, D, G, J, O, P, Q, R, S, U), start by drawing the straight lines (if any) described above. Then, draw the curves in a single, smooth stroke. For example, for 'B', start with the vertical line, then draw the top curve from left to right, and finally, the bottom curve.

Numbers

Numbers are drawn similarly, with straight lines drawn from top to bottom, left to right, and curves drawn in a single stroke.

Consistency

The key to good single-stroke lettering is consistency. Keep all your letters the same height, and maintain consistent spacing between letters and words.

Remember, the goal of single-stroke lettering is clarity and readability, so avoid any unnecessary flourishes or decorations. You can create clean, professional-looking lettering for your engineering and architectural drawings with practice.

Figure \(\PageIndex{1}\): Numbers

Figure \(\PageIndex{2}\): Letters A through J

Figure \(\PageIndex{3}\): Letters K through Q

Figure \(\PageIndex{4}\): Letters R through Z

Guidelines:

A common problem for students is to draw guidelines but forget to use them. Guidelines are very light lines laid out with a 6H or harder pencil. It's essential not just to draw the guidelines but actually to use them. The letters' height and position must be controlled to letter by hand appropriately.

Letter Height:

The letters must be large enough to be read and reproduced clearly. The minimum height of letters on a printed drawing is 1/8 inch (about 3.0 mm). The letters for the title block on large (D size and above) are 1/4 inch (about 6.0 mm). Letters that are used to indicate section views should be 1/4 inch tall.

Letter Spacing:

Try to maintain an equal amount of space between the letters. There should be adequate space between the letters, but not too much. The letters' shapes influence how closely they should be placed together. For example, the letter "A" would be placed closer to the letter "T" than the letter "M" would be to the letter "I."

Row Spacing:

Like the spacing between letters, the spacing between rows can be too large or too small. There should be a minimum of half a letter height between rows of text. If two rows of text are not meant to be read together, be sure there are greater than two text heights between them. As a rule of thumb, use 75% of the letter height for the space between rows.

Other Options:

All lettering on a drawing should be done in upper case. Some companies prefer that the letters be slanted like italic letters. This option is not covered in this text in the interest of simplicity. When revising an existing drawing, personal preference is not an option. You must letter in the same as the original drawings.

Remember, practice is critical to mastering lettering in engineering graphics.