I just used this simple trick.
I was getting ready to paint the wheels on my truck and needed to keep the paint off the tires. I did this and it worked:
Mask around the rim protector or outside flange of the wheel, whichever surface presents itself. Then meld down one of your wife's candles. Brush the melted paraffin all over the tire, your hands and whichever pet's nose is poking in your business. Spray paint until surface is equally covered in runs, then allow paint to dry. Use hot water to hose off paraffin wax, and drive on!