People put patches on their riding jackets and vests all the time because it's very easy to see those patches. Patches on hats, saddlebags, and belts are also somewhat easy to see. You can even show off patches on your wallet. But what about patches on your pants? The problem here is that the largest area, the back side, is often not seen because you're setting on it! Long coats and un-tucked shirts also cover most of your butt, so patches on your pants are hard to see. But you can add patches to your pants for a few reasons.
The first thing you probably think you'd use patches on jeans and other pants is, of course, to fix rips and holes. However, there are some problems with this. Typical motorcycle patches are fairly thick; thicker than standard patches used to repair clothing. If you put one on the knee, it will be difficult to bend the clothing. Using it anywhere near the knee might make it difficult to kneel down.
You can put patches on your pants for decoration, but just be aware that people will be staring at your bottom a lot. You also might want to put the patches on the back pockets. This makes it easy to center them, and it puts them down low enough that most jackets won't cover it. You can also put them on the sides of your pants under the pockets, although they will have to be pretty small.
Most people don't put patches on their pants unless they're the thin ones used to cover rips. However, it can be done if you look for small patches and space them correctly.
