As students read, they can jot down tricky vocabulary words. In the past, I've used post-its and it has become very messy. With these bookmarks, they can take ownership of their vocabulary acquisition. With their vocabulary words in one place, students can then add definitions in their notebooks and refer back to the bookmark as needed.
For sturdiness, it is reccommended to print on cardstock. In addition, students can decorate the alternate side of the bookmark to their own taste.
Hope you enjoy!