I sold a collectible this year and I’m trying to figure what the tax rate will be on my gain. Is it my tax bracket (15%) or the rate for collectibles gain (28%)?

The special capital gain rates are supposed to allow taxpayers to pay less tax on these gains than on ordinary income. Thus, the special 28% capital gains rate for collectibles applies for taxpayers in the 28%, 33%, 35%, or 39.6% tax bracket; the rate for those in the 10%, 15%, or 25% bracket is effectively the same as the rate on ordinary income. The reason: The capital gains rate is the maximum rate; it cannot exceed the overall rate paid by a person on taxable income. Of course, the collectible gain part of taxable income and can raise the tax bracket for an individual (yours may be higher than 15% after including the collectible gain in income).