Let V be the number of yards of velvet fabric Louis bought.
The silver thread cost 2 * 3 = $<<2*3=6>>6.
He spent 24V + 15 + 6 = $141 on the suit.
The fabric cost 24V = 141 - 15 - 6 = $120.
Thus, Louis bought V = 120 / 24 = <<120/24=5>>5 yards of fabric.
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