SIX REASONS WHY:
A LECTURE ON
LINEWEIGHTS AND
WHY IT MATTERS
AR. JOANNA PATRICIA GRANDE, UAP
FROM https://www.oca.ac.uk/weareoca/interior-design/six-examples-of-why-line-weights-matter/

INTRODUCTION
In any design drawing, both sketches and technical drawings, the unsung
hero of the drawing is line weight. Varying the line weight, that is the
thickness of the lines, will always add more depth and character to your
drawings. Even the simplest of drawings will look more polished and
professional with a bit of line weight variety. Let’s look at some examples
to see what I mean.

THE CUBE
REASON #1

WHAT DO YOU
SEE/PERCEIVE?

WHAT DO YOU
SEE/PERCEIVE?

WHAT DO YOU
SEE/PERCEIVE?

WHAT DO YOU
SEE/PERCEIVE?

WHAT DO YOU
SEE/PERCEIVE?

WHAT DO YOU
SEE/PERCEIVE?

HOW ABOUT NOW?

Look at these 6 cubes. These are all composed of the
same lines, same angles, etc. The two on the left have
no variety in the line weight, whereas the other 4 have
a different hierarchy . these all show a cubic volume
but what do you see in the ones with a varied line
weight? Do you see a cube with one corner closest to
you? Do you see 3 planes coming together to create a
cubic space?

THE
PERSPECTIVE
SKETCH
REASON #2

SPOT THE DIFFERENCE

Let’s look at these hand drawn perspective
sketches. For the drawing on the left, nearly even
pressure was applied for every line. For the drawing on
the right, on the other hand, heavier pressure was
applied on lines representing objects that were closer
to the viewing position while lighter pressure was
applied on lines representing objects that were farther
from the viewing position. One drawing starts to look a
bit more cartoon-like while the other has just a bit
more character and depth. This is all down to line
weight.

THE PLAN
DRAWING
REASON #3

COMPARE

Varied line weight in plan is essential. A drawing that
has no variety in the line weight will look either dull or
busy. In this plan drawing on the left, the same line
weight is applied throughout. As a result, the drawing
just looks a bit messy even though there’s a nice level
of detail. Alternatively, the same exact space is drawn
with variety in the line weight. The walls and elevation
symbols are drawn thicker. This is especially important
for the walls to show that they are ‘cut’ objects. The
furniture and the joinery is drawn a bit thinner, and the
details like the floor pattern are shown very thin where
they aren’t as visually dominant. This creates visual
depth even though it’s a 2D drawing.

THE ELEVATION
DRAWING
REASON #4

COMPARE, AGAIN

Similarly, let’s look at how line weight works in this
elevation drawing. On the left, everything is drawn at
the same line weight. As a result, the kitchen and the
dining area beyond it start to visually blend together.
It’s difficult to understand how these spaces interact.
Alternatively, the drawing on the right shows the dining
area drawn thinner and lighter compared to the
kitchen. This helps indicate that it’s a space that exists
further behind this kitchen counter.

THE SECTION
DRAWING
REASON #5

COMPARE, AGAIN (1)

In section drawings, line weight is most important in
showing what is ‘cut’ by the section line versus what
appears in elevation beyond the section line. Take
these two section drawings of the Villa Capra Rotonda
(See this Section Drawing blog post). The one on the
left has no variety in the line weight where the one on
the right shows the ‘cut’ walls, ceilings, and floors in a
much thicker line weight compared to the architecture
beyond the section ‘cut’. This slight difference makes
one drawing very apparent in showing an interior space
and one just a bit confusing.

THE DETAIL
DRAWING
REASON #6

COMPARE, AGAIN (2)

On the left, there’s no variety in line weight while on
the right there is. Just as with the full building section
drawing, here showing the ‘cut’ objects with a thicker
line weight than the objects that are seen beyond the
‘cut’ of the section detail helps visually indicate how
these objects relate to each other three-dimensionally
despite being a 2D drawing.

THANK YOU
FOR LISTENING