White Denim

Some are. It depends on the weight and density of the cloth, since white denim has no dye to block light the way indigo does in blue jeans. A pair at ten ounces or heavier is opaque in most light. A lightweight white will show shadow in direct sun.

The reliable test is to stand in front of a window with the light behind you and look in a mirror. Fitting room lighting will not tell you.

Nude or blush underwear in a shade close to your own skin tone, in a seamless cut. White underwear is the one thing that shows through white denim clearly, because the two whites are almost never the same shade and the edge of one against the other is visible.

Seams and lace both print through under a lightweight denim. A smooth microfiber is the safest choice under anything pale.

Ten ounces or heavier is the usual threshold for a white denim that stays opaque in daylight. Between eight and ten ounces, opacity depends on how tightly the fabric is woven. Under eight ounces you should expect some light to pass through, particularly when the sun is behind you.

Rigid cotton tends to be more opaque than a stretch blend at the same weight, since elastane needs a more open weave. The product page usually lists the weight.

Yes. The rule against white after Labor Day dates from a period when it signaled who summered where, and it has had no practical force for decades. White denim works through autumn and winter, and it works better when what you wear with it is seasonal: wool, shearling, boots.

Winter white as a full head-to-toe outfit is a separate idea and takes more commitment. A single pair of white jeans under heavy layers is the easy version. Frida in White Oak is a favorite for its heavier-weight, off-white denim, with a substantial feel that works especially well in colder months.

Wash them cold, on their own or with other whites, and skip the fabric softener, which leaves a residue that grays over time. Air dry them out of direct sun. Heat sets stains and yellows cotton, so the dryer turns white jeans dull faster than anything else.

Oxygen bleach is safer on cotton than chlorine, which can yellow it over time. Wash after every three or four wears rather than every wear.

Treat it while it is fresh and always with cold water, since hot water sets most stains permanently. Blot rather than rub. For oil, work a little dish soap into the mark before washing. For wine or coffee, use cold water and oxygen bleach applied directly to the spot.

Check the spot is gone before the jeans go anywhere near heat, because a dryer will lock in whatever is left. Denim hems pick up gray from sidewalks, and a soft brush takes care of that.

Eight pieces. Five jeans: Frida in Alabaster, Regina in white, Billie in Alabaster, Robbie in white and Maria in Chalk. Three shorts: Rebecca Short, Steph Short in Skim and Billie Short in Bone. Rises run from low through mid to high across the group.

The whites are not all the same shade. Alabaster, Chalk, Bone, and Skim each sit slightly off a true white, which matters if you plan to wear two together.

Almost everything, which is the practical argument for owning a pair. White holds its ground against black, navy, olive, tan and every shade of blue denim, and it is one of the few bottoms that takes a bright color without the outfit tipping over. Cream and ivory need care.

Two off-whites close in tone will look like an accident rather than a decision. Put clear distance between them or commit to one.