Photography: Ava Porter Words: Brie Noel Taylor The setting sun is casting a gentle hue of orange-pink across brick facades of San Francisco's Post street, and the last glints of daylight are catching in the city's small windows. I'm in the uppermost part of the Tenderloin, loitering below an unlit sign for Mack's valet cleaner. The sign is rare, I'm about to learn, because it's painted with porcelain - an expensive, hard to maintain style of neon sign creation that went out of style sometime around the 1980s. I'm loitering beneath this particular sign in this particular part of the