MAC Sin is a slightly cool-toned, medium-dark burgundy with a matte finish. It is a permanent lipstick that retails for $19.00 and contains 0.1 oz.
MAC Sin Lipstick ($17.50 for 0.10 oz.) is described as a "deep dark blue red [with a Matte finish]." It's a dark, burgundy-red with subtle cool, fuchsia-ish undertones with a matte finish. It had mostly opaque color payoff, though it is buildable to fully opaque color. I think it is only when you try one of MAC's original Matte formulas and then immediately try one of their newer shades that you can appreciate the improvements they've made. The texture of this is much drier, so it does drag and tug on the lips somewhat. It was a bit drying over time, though the color lasted for over seven hours. NARS Ingrid (P, $32.00) is glossier. NARS Liv (P, $32.00) is cooler-toned, glossier. Kat Von D Motorhead (P, $21.00) is cooler-toned. MAC Talk That Talk (LE, $16.00) is is cooler-toned. MAC Soulfully Rich (P, $18.00) is darker, cooler-toned. MAC Endless Drama (P, $18.00) is less matte. MAC Prince Noir (LE, $16.00) is darker, cooler-toned. See comparison swatches / view dupes.
FURTHER READING: Formula Overview, which is a detailed review of the range as a whole.
Formulated to shade, define and showcase the lips, M·A·C Lipstick is available in every nuance of your favorite color and high-fashion texture. It's the iconic product that made M·A·C famous. AMPLIFIED CREME (A): Ultra-creamy. Quietly shiny. Color-packed! Hi-res: hi-impact. CREMESHEEN (C): Creme-based lipstick that imparts bright full color, with a soft and supple shine. FROST (F): Excellent color payoff with medium to high frosted shimmer-and-shine finish. LUSTRE (L): Demi-sheer with wet-look lustre finish. Very slick. Makes lips look soft, smooth, ultra-moist. MATTE (M): Pigment rich with intense color pay-off. No-shine, all matte finish. SATIN (S): Color-rich. Soft satin, semi-matte finish. Conditions while adding intense color.