Simply put, these are codes we assign to each case, composed of characters
identifying a material, its structure, number of layers used during measurement,
and treatment applied (e.g., laundered), if any. While we provide these codes
for reference back to the associated paper, in most instances the reader can
ignore these codes.
For those more interested:
The first letter or pair of letters generally denotes the material structure,
using W for woven materials, K for knit materials,
CP for cut pile materials (e.g., corduroy), and nW for non-woven
materials. Composite masks, such as the N95-compliant materials tested,
have different codes (e.g., ASTM for surgical masks that adhere to the
The different material structures can be added or removed from the plot using the
checkboxes in the controls above the first plot.
The second component is a number used to identify the different
materials within a given material structure. As the number is only
used to identify the material, it does not contain any information
about the material makeup or structure.
Next, some codes append x* to denote if multiple layers
were used during the test. For example K4x2 is four layers of
the K4 material (Double-knit jersey, yellow). If the x*
component is missing, a single layer of the material was used.
Finally, some codes append a space followed by a code denoting if
a sanitization treatment was applied to the material. Examples include,
HS for heat treatment, IPA for isopropyl alcohol treatments,
WD for laundering, and SW for washing with soap and water.
If no such code is appended, the material is in its original condition.
If santization was repeatedly applied, this latter part of the code
will also be appended with x* (e.g., WDx10 denotes
materials laundered ten times).
For example, a code
denoting a knit material that has been laundered multiple times is
K4x4 WDx4. A list of the codes is included in the table at the bottom
of this page.