reasonable basis.

16 CFR 423.6 makes it an unfair or deceptive act to fail to possess, before sale, a reasonable basis for all regular care information given to the purchaser, and the same section says that basis must be reliable evidence the product was not harmed when cleaned according to the label. The clause decorators miss defines what an instruction is: the rule requires evidence for "instructions when silence has a meaning", and its own worked example is a shirt labelled machine wash, tumble dry, cool iron, where saying nothing about bleach asserts that bleach is safe. A decorated garment is a different product from the blank, so the blank maker's label is evidence about undecorated fabric and nothing else. Nobody has tested what the print does at that wash temperature unless the shop tested it. The honest routes are to test the decorated garment or to narrow the label, because the rule does not ask what the fabric survives; it asks what the thing you sold survives.