The technique of piggybacking perm rods is used to create a uniform, spiral-like curl in very long hair. Without this neat little trick, you'd likely end up with very curly ends and sagging, barely-there bumps at the root. By dividing the curling workload between two perm rods, wrapped back to back, each section of hair will form the same sized curl from root to tip. This method is perfect for those with super-thick, long hair or anyone who's hair length is past their shoulder blades. So if you resemble Rapunzel, this wrap's for you.
Divide the hair into four equal sections. Make a part from the middle of the front hairline, all the way to the middle of the back hairline. Make a part from the tip of one ear, to the tip of the other. Hair clips are your best friend here -- use them to keep each section of hair up and out of your way.
Piggyback perms are always started at the back of the head. Release the clip from one of the back sections and section off a 1-inch thick section, horizontally, along the bottom with a tail comb. Clip the rest of the hair back up and repeat this with the other back section.
From the middle of your 1-inch, horizontal section carve out a 1/2-inch wide section of hair. This 1-inch by 1/2-inch section is going to get twirled around the first perm rod.
Grab an end paper and fold it lengthwise. Sandwich your small section of hair between the fold in the end paper and slide that end paper down to about half way down the entire length of your section of hair.
Hold the perm rod at a 45-degree angle with the open end of the rod toward the top. Begin to wrap that hair around the perm rod in a spiral-like pattern, keeping the unwrapped half of the section out of the way. Keep on wrapping until the hair reaches the bottom of the perm rod. If you haven't made it to the roots of that section yet, you can continue the spiral wrapping pattern, working your way back up the perm rod until you reach the roots.
Lay the perm rod flat against the scalp (the perm rod will be sitting vertically) with one hand and use your other hand to grasp the "cap" of the perm rod. Pull the cap upward so the elastic band lies against the scalp and snap that cap into the open end. If you've placed the elastic right, your perm rod should sit snugly, instead of wobbling like a bobble head.
Grab another end paper, fold it lengthwise and sandwich the ends of the remaining hair sticking out of the first perm rod. Hold the second perm rod horizontally and wrap the section of hair, starting at the ends, until the second perm rod comes in contact with the first. Secure the second perm rod in place by laying the elastic across the top of the perm rod and placing the cap in the hole. You now have two perm rods "piggybacking" each other.
Repeat this piggybacking process for every 1/2-inch section in that horizontal row of hair. When that row has been wrapped, take the two back sections and carve out another 1-inch wide horizontal section. Wrap that one up as you did the first one. Keep repeating this process until all your hair is wrapped and your piggies are tired of standing there (yeah, the process takes a while).
Once all the hair is wrapped take a second look for any perm rods that are dangling and tighten them up by rolling them until they sit snug against the scalp or other perm rod and adjusting the elastic to keep the rod in place. You can now apply the perm solution and give your poor wrists a break.
Keep the hair moist when wrapping it in the perm rods. Moist hair behaves much better than dry hair does when wrapping it.
Always buy at least two perms when doing a piggyback wrap. If your hair is long enough to require this method of wrapping, one perm solution is not going to cut it.
When applying the perm solution be sure to soak every little bit of each perm rod. Move those rods around a bit if you have to so you get every nook and cranny saturated.
Sure, you want the perm rods snug against each other, but don't put undue stress on your hair. Perm rods that are wrapped too tight run the risk of breaking off your hair once the perm solution is applied. Remember -- snug = good, super-tight = bad.