The PaintShop series of acrylic lacquers from Dupli-Color creates nice webbing. They have jet black and bright silver options. You can find it at O'Reilly Auto Parts for $25. Amazon sells it, too.
The trick is that this stuff is "ready to spray" so you have to let some of the solvents evaporate before it will stream out of your gun in a webbed pattern. I pour a small amount (maybe 4 ounces) into a mason jar and let it sit overnight. When you put it in your gun, you might need to re-add lacquer thinner to obtain just the right consistency. Have lots of scrap cardboard on hand to test.