Small deposits of tar can be removed by letting them harden and then carefully cutting them off. For larger deposits, soak the areas with vegetable oil for 24 hours. This will soften the tar, which then can be removed by shampooing. You may need to bandage the oil-soaked area or put a T-shirt on your pet to prevent your pet from licking or chewing off the tar. Never use gasoline, kerosene, turpentine, or organic solvents on your pet. These products can severely burn your pet's skin and cause toxicities.
For those of us who live among many pine trees, note that vegetable oil or butter can also be used to remove pine pitch.
Paint is best removed by letting it harden and then clipping off the affected areas. Avon's Skin So Soft may soften some oil-based paints, which can then be removed.