Fifteen percent of the surface
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The trimmings exemption has a ceiling and the ceiling is an area
Decorative trim or a decorative pattern or design is exempt provided it does not exceed 15 percent of the surface area of the household textile article.
Which measures something weight cannot reach
Embroidery thread is light. A design covering a seventh of a shirt could be a fraction of a percent of its weight. Measured by weight the rule would never find it; measured by area it does.
So one part of one title carries two incommensurable thresholds
Five percent by weight suppresses a fiber name. Fifteen percent of surface area removes an exemption. Neither number can be converted into the other and neither is a substitute for the other.
Across this library that is a seventh way a rule has been indexed
The others are panel area, proportion of label space, a flat floor regardless of size, container volume combined with characters per inch, total surface area, and an area-weighted average over wetted surfaces. This is the first case of one part using two measures at once.
The rule also prescribes a phrase for the honest middle case
If no representation is made as to the fiber content of the decoration, and its fiber content differs from the basic fabric, the fiber content designation of the basic fabric shall be followed by the statement exclusive of decoration.
Which is a disclosure of a boundary rather than of a content
The statement does not say what the decoration is made of. It says that the numbers given do not cover it, which lets a reader know the edge of what has been measured.
And there is a second prescribed phrase at a third threshold
Elastic material that is part of the basic fabric may be treated as a finding where it does not exceed 20 percent of the surface area, provided the fiber content information is followed by the statement exclusive of elastic.
Three numbers, three different jobs
Five percent by weight, fifteen percent of area, twenty percent of area. The first changes a name, the second removes an exemption, the third permits a reclassification. Reading them as a single scale would be wrong.
The part has a fourth area threshold elsewhere, on a sample
A sample, swatch or specimen need not be labeled if it is less than two square inches in area and the required information is disclosed clearly, conspicuously and non-deceptively on accompanying promotional matter.
And a fifth on a flag
The covered product list reaches flags with a heading or more than 216 square inches in size. A small flag with no heading sits outside the list, which is a size test on a product rather than on a label or a decoration.