As suspected you're doing everything wrong from the way the products are intended. After you tool, stamp whatever, you should have the back already taped to avoid any stretching from any tooling. Leaving the back taped protects it from getting antique on it for a cleaner finished belt which you could dye but don't use antique on the back. As @Dwight said above dilute the resolene 50/50 with water. To antique something as its intended use oil first, then put a coat of resolene on it and let it sit/dry. That's when you apply antique then remove right after. That's why antique comes in so many different shades is it high lights tooled or stamped pieces to almost black in back grounded areas then the non tooled parts should turn the color of the antique you pick so if you get antique on the edges is fine just buff with canvas or old denim. If you want to dye the back use dye, even then after it dries you should buff it with canvas. Either way don't wax the backside of the belt. Then apply another coat of resolene over the antique, edges and backside or something like Tokonole then use a slicker to smooth out the backside.