I always thought those cardboard cat scratchers were a stupid idea, until one time when we were moving and there was a stack of boxes, and the cat could NOT leave it alone. Well. She left it alone for a bit after pulling the whole stack down onto the floor with a crash. But she was right back at it in no time.

But it seems lame to spend money on cardboard, something thrown away so often and in such quantity it gets its own dumpsters. Seriously? We're basically talking about buying trash for the cat to play on!

But cats love it! But it's just cardboard! And I'm cheap! But... think of the cat!

Psychologists say it's not good to live with this kind of internal conflict.

Much of my current furniture came from Ikea, and everything comes from Ikea in cardboard. Even my change and receipt were in a cardboard flat-pack last time I went there. My place was filled with new furniture I didn't want scratched on, and cardboard. The light bulb went on.

This project is quite similar to Neopirater's, with two notable exceptions.

1) No glue on mine. It's all held together with magnets*.

2) My cat is much, MUCH wider than Neopirater's cats. It's even possible my cat is as wide as any two of Neopirater's cats. As a result, although I don't think my scratcher is much smaller, it will look much smaller in the final photo.
2a) She's not fat. She's just wide. I swear!

That was a joke. I mean, there's really no glue. But there are also no magnets.

Step 1: What You Need

WARNING: It's *highly* recommended to read the instructions all the way through before beginning this project, because there are option steps, and because some of it will make more sense if you know what comes next.

MATERIALS & TOOLS

Cardboard from Ikea (This is an Ikea hack, after all!)
--- One long skinny box a bit bigger than a cat (Here, I've used the one the HELMER drawer unit comes in.)
--- The outer flat packing boxes of larger furniture (I used the VIKA Blecket box & inserts.)

Utility Knife
--- Must be sharp! Otherwise the cardboard just shreds, and your cat eats the shreds and craps cardboard bits for a week, instead of getting a new scratcher.
--- Adjustable depth of blade helps, you will NOT be cutting all the way through the cardboard.

Straight Edge, 1-2" wide, as long as your skinny box is long
--- Preferably metal
--- Need not be an actual ruler, as there is no actual measuring involved here.

Packing Tape
--- Duct tape is an acceptable substitute, as is strapping tape. The point is, you're going to be putting a little tension on this tape, and don't want it to break.

Although you don't need a cat to make this scratcher, it seems wise to have a cat somewhere in your life. I mean, if you don't even know a cat, you should probably go make something else. Maybe a nice trivet, if you're thinking about things you can put under other things.

Step 2: Setting Up Shop

Be sure your long, flat box is the right dimensions for your cat. Ideally, it's about as long as your cat is from nose to tail tip, and about twice as wide as your cat, and about as deep as your straight edge is wide... If the old wives are to be believed, your cat is approximately as wide as its whiskers. Even if it spreads out like a hot breakfast when it's sitting down.

If your base box is a little too big, you can cut it down, just make a straight cut all the way down the long way, bring the two halves together by the right amount, and run a strip of tape down the seam on the outside of the box. It's not load-bearing tape, but it will prevent the box halves from popping apart during the final step.

If your base box is too small... find another box. Or make a base out of yet another of those many pieces of cardboard hanging around.

!! DO NOT ATTEMPT TO ADJUST THE SIZE OF YOUR CAT !!

Take a good look at your big sheets of cardboard, and figure out which way the grain goes. Look at the sides... two sides will have triangles, and two sides will not. You want to position the cardboard with the triangle sides left and right, and the sides without triangles at top and bottom. When you are cutting, you want to cut across the triangles as you pull your blade toward you. If you cut with the grain, it's not as fun to scratch on (or so I'm told).

Step 3: The First Cut

Line up the straight edge with the left or right side of the cardboard.

(Put the straight edge on the left if you're right handed, put it on the right if you're left handed. Hmm. If you don't know how to use a straight edge, you're probably not OK to use a utility knife. Maybe you should do some other project?)

Holding the straight edge firmly in place with one hand, cut down the length of the cardboard with the blade in your other hand.

Cardboard has (normally) 3 layers - a flat sheet, a corrugated layer (the triangles we talked about), and then another flat sheet. It's OK to use double or triple wall corrugated cardboard, you just have to cut a lot deeper, and still take care not to cut through the bottom-most flat layer. The total number of cuts you have to make can be divided by the number of layers your cardboard has.

You want to cut through the top sheet and at least half way through the corrugated layer, but NOT through the other flat sheet. You need that to hold the whole thing together.

Step 4: All the Rest of the Cuts

Now flip the whole sheet of cardboard over. Take the straight edge and knife off it first, unless you're into minor catastrophes.

You just made a cut in the other side. That makes a kind of flap. Bend that flap upward, so all the long flat of your cardboard is still on the table, but there's a flap as wide as your straight edge sticking up in the air. Place your straight edge against the bit that's sticking up.

Holding the straight edge firmly in place with one hand, cut down the length of the cardboard with the blade in your other hand.

From here on out, it's lather/rinse/repeat: Flip the sheet over, bend the flap, line up the straight edge, make the cut. Keep doing this until you get to the far edge of the sheet. (Definitely stop when you are out of cardboard!) It doesn't really matter if your last flap is a little short or long. Unless you're OCD.

It is probably easier and slightly faster to cut all the way through and glue the strips together, but I've never been good with waiting for glue to dry, and my cat has pica, which means she'll eat just about anything. She has a preference for plastics, and she'd be very likely to eat even a tiny bit of glue sticking out somewhere.

Step 5: Optional: Mod for Vertical Installation

Additional Materials:
- Hook & loop straps
- Butter knife

Find some hook & loop straps, like the kind used to bundle electronic cables together. These are available cheaply from most hardware and office supply stores. If you want to pay more, but maybe get more options, or possibly better hook & loop material, or are too precious to go to an actual hardware store, go to a sewing supply or a store with a sewing section, and buy the necessary amount. Velcro is a trade name, and will likely cost at least 30% more than any other kind of hook & loop product.

The necessary amount is 2 strips five times the width of your table leg. This will give you sufficient overlap to make mounting the scratcher vertically fairly secure. By 'strip' I mean a PAIRED strip--you need the hook & the loop side, or it won't hook. The scratcher will just fall on the floor and you'll feel like a jerk. And your cat will laugh at you.

Use your utility knife to cut 2 pairs of slots in the base box of your scratcher. You want them to be equidistant from the long-way center line, and about a hand-width from the ends of the box. If your hands are unusually wide or narrow, please have an adult with normal size hands help you with this part.

The space between the 2 slots in each pair should be the width of your table leg (or whatever you're attaching the scratcher to). Each slot should be the same length as your hook & loop material is wide.

Use the Ikea SVIT butter knife to push the straps through the slots, taking care that the overlapping, hook-able part is outside the box. If you care about the finish of your table leg, you'll want to see which way the hook part of the hook & loop is pointed, and adjust so it's not going to come in contact with the finish.

If you use any other butter knife, the project will explode, voiding your insurance and disappointing your cat.

Step 6: Assembly

Take all your folded up cardboard accordions and stuff them into your flat box. It should be kind of a snug fit, but you don't want to burst the box. If it's very loose, go back to Step 4 and cut more accordion. Or cut the box down.

Run a strip of packing tape twice around the outside of the flat box, taking care to pinch the corners in a little bit. This will lock interior cardboard in place.

You're done now, put the thing on the floor and bask in the reflected glow of a very happy cat.

If you added the optional vertical mounting straps in Step 5, now's the time to strap it to your table leg or whatever. If your cat doesn't care for the vertical position, you'll still be able to lay it flat on the floor. And if you *didn't* do that bit, and your cat would prefer a vertical scratch, just cut the tape, pull the cardboard accordion out, put mounting straps in, and then re-do the final assembly.

Feel free to add catnip to the scratcher to entice your kitty. Many cats seem to intuit the proper usage in no time at all.

Step 7: If...

If this is your cat's first cardboard scratcher, put it near where she likes to sleep, and occasionally place the cat on the scratcher just as she's waking up. Cats like to stretch and scratch right at waking, and it doesn't take them long to learn that the cardboard "tree bark" is the ideal place to do that. Our cat naps right on the thing to save time commuting. We've found scooping the cat up out of her nap, and pouring her onto the scratcher (front feet first) seems to give her a pre-stretch that leads to scratching every time.

If the cat really, truly does not seem to know what to do with it, scratch on it with your own fingernails while he watches. The motion and sound are both useful because cats learn easily by imitating us. You can also gently rub his front paws on it, to further provide the idea. Try not to freak him out, or he'll never go near the thing again.

Most adult cats won't actually climb the thing, since it is only about as long as their body, but it's better if it's not attached to something unstable or very light. For instance, a mop handle is a poor choice. You can also just lean it up against things (walls, the end of the couch where she used to scratch...). Our cat learned the exact technique for getting better scratch without knocking the thing down.

If the top surface of the scratcher gets all used up and ratty looking, just cut the tape, flip the accordion over, and re-tape it.

If your cat dispenses bodily substances onto it or something spills on it, or it gets rained on, remember that cardboard is absorbent, not washable, and free. Cats who get a lot of hairballs like to stand on the scratcher to vomit, because it gives good traction, but usually they puke over the side.

If your cat is a sheep, like our cat, you may want to get the shed hairs off it with the cat's brush, or even vacuum it occasionally. This will be somewhat traumatic to the cat if he is on it at the time.