Whether you're re-wrapping an existing cat scratching post or making a new one, if you're using rope, you'll want to know what and how much to buy.
How much rope you need can be determined by how thick the rope is (1/4" or 3/8"), the circumference of the post (how much rope it takes for one wrap), and the height of the post you need wrapped (how many wraps you'll need to make). While you can do the math yourself, I've made it easier by creating a calculator where you just put in the three measurements.
What type of rope should I use?
The type of rope you typically see on scratching posts is twisted sisal rope. It's generally sold in 100 foot rolls. You just need to know how many rolls to buy so you have enough but not more than you need.
What size rope should I use?
1/4-inch and 3/8-inch are the typical sizes used for scratching posts. The 1/4-inch sisal rope is easier to work with and fasten to the post. The 3/8-inch sisal rope is thicker and more durable. Because it's thicker, you also don't need as much 3/8-inch rope to wrap the same amount of post. If you're simply re-wrapping a post then it's probably easiest to just measure the thickness of the existing rope and buy more of the same. If you're making a new post then consider ease of wrap (1/4-inch) versus durability (3/8-inch).
How much rope do I need for one wrap?
If what you're wrapping has the same circumference from top to bottom (i.e., it isn't wider at certain places than others) then each wrap will take the same amount of rope. To measure one wrap (if you don't have a flexible tape made specifically for this sort of thing) simply use a piece of string or rope and a measuring tape or ruler.
- Wrap the string or rope around the post
- Pinch and hold on to the point where the end meets the rest of the string or rope
- Straighten the string or rope and measure from the end to the point that you've got pinched in your fingers
If your post is more oddly shaped then measure a place that seems to offer an average circumference (e.g., for a cone shaped post measure a point in the middle).
How many wraps do I need?
Now that you know how thick each wrap is (how thick the rope is you'll be using) and how much rope is used in one wrap (the circumference), you'll need to determine how many wraps you'll be making. Do this by simply measuring the height of the post where you'll be wrapping it (there will likely be a part of the post that will not be wrapped so be sure not to include that in your measurement).