With the possible exception of his purple tailcoat (which we’ll examine shortly), perhaps the most iconic staple of the Joker’s costume was his Victorian-style high-waisted trousers.
And here are a couple excellent close-up photos of the trousers, from an auction listing:
The trousers had a sewn-on waistband which overlapped by several inches in the front:
Here are a couple additional screen-used Joker costume display photos (which I’ve cropped) in which the waistband is directly observable:
(Note that the waistband was cut on the crossgrain, and care was taken to properly align the plaid patterns at the center front.)
The Joker’s suspenders also fastened to his trousers on the inside of the waistband, rather than the outside:
In fact, Bob Ringwood & co. did such a wonderful job with the Joker that even his suspenders (which would theoretically never be seen in the film) were stylistically consistent with the rest of his costume ensemble!
The upper front of the trousers had a pair of forward pleats on each side:
These pleats were not sewn together, only pressed and sewn into the waistband.
The Joker’s trousers had side pockets (or, perhaps, pockets cut at a very slight diagonal to the side seam).
Although the purple trousers he (Jack Napier) wore with his three-piece suit early in the movie had cuffs, the plaid ones he wore for the remainder of the movie did not.
The costumers took care to properly align the plaids along the front fly, as well as the center front and center back seams (which can be a challenge, so kudos to them, right?!?).
