20 month old, should I introduce a scissors?

We haven't given DD scissors yet (she's almost 27 months). I just looked online and couldn't see any that were designed for kids under age 3.

Kids scissors are usually labeled for ages 5+. I've seen a very few labeled for ages 4+. Even the ones with the safer, rounded tips can still cut if you pinch with them, and I really cannot see giving them to a 20-month-old. DD has used scissors in preschool and she is 3, but I think that would be about the youngest I'd give a kid scissors, and only under direct supervision.

When I taught preschool, we introduced scissors in the 3 year old room, but only a few 3 year olds could use them. About half of the four year olds could use them, and most 5 year olds.

I've just read a Toddler & Two's art book. Here is what it said about toddlers and scissors:

Toddlers are intrigued by scissors. The safest first scissors experience is safety scissors to let them cut thing playclay rolls ("worms"). A good second experience is to help them cut small strips of yarn held taut by an adult. Finally, the more advanced third experience is to let them cut strips of construction paper independently. Don't expect them to master cutting paper until they are well over 3 yrs old.