Experimenting with the Flour Sack is one of the best exercises you can do as an animator. It allows you to play with squash and stretch, shape change, and weight while still maintaining a simple character bursting with life. Unfortunately one little mistake can take your lovable flour sack and turn him into a roasted turkey, with all the appeal of a lifeless corpse.
What is essential to keep in mind is that this is not an exercise in muscle and anatomy. The terrific thing about the Flour Sack is it HAS no muscle or bone. It’s perfectly flexible. The tricky thing becomes when we want to use his ties- the little floppy tufts at the corners- as we might use the limbs of a human character.
The ties on the Flour Sack are there to allow some extra play and humanization of the simple animated shape. Without them you have a much less expressive shape.
As humans we love giving human qualities to non-human objects. We name cars, refer to our favorite sports equipment (baseball bats, tennis rackets, etc.) as he or she, and take great pleasure in looking at photos of kittens and puppies that appear to be smiling in a very human-like way.
So the ties on our little Flour Sack serve an important audience-relationship-building purpose. However they only represent arms and legs, they are not actually arms and legs!
You may come across Flour Sack animations that have the sack walking as if on little legs, portrayed by the lower two ties, as directly above. The problem with this is that it ceases to be the flour sack and instead becomes a humanoid character. There’s nothing wrong with animating a humanoid character, you’ll spend most of your career doing just that most likely. But we lose the purpose of the Flour Sack when we MAKE him a humanoid character.
Take a look at these two images:
The Flour Sack on the left (Image A) uses all of his mass to take a step. The “foot/leg” planted on the ground is actually just having more flour inside his right bottom quadrant. Compare this to Image B where the tie is an absolute leg, not just an extra bit to add some appeal. Here the sense of weight of the flour is gone. Instead we have two forms supported by muscle (and possibly bone, depending on how stiff you keep the pretend leg).
This removes a great deal of fluidity from the simple flour sack, and in practice turns it much more into a “roasted turkey” instead.
Imagine for a moment you are physically squeezing both types of flour sacks in your hands. This illustrates extremely well the difference these two choices can make. The left, Image A, is going to be pillowy and soft. The flour will move around your fingers and redistribute. The B flour sack with muscle, though, will feel like squeezing a roasted chicken. It will give way and be squishy as a cooked bird might, but with much more meat and solidity than the flour-filled sack.
The point is to remember that the ties of the Flour Sack are like jewelery. They are there to add to the experience. Their ultimate purpose for existing is to increase expression and performance of your character. If you take them away you should still have a weighted, functioning creature- just one that looks a little less human. However: if you take away the ties and your animation is floating off the ground or lacks weight, it’s time to go back to the drawing board because you’ve missed the purpose of the flour sack’s existence.
One Last Thing…
The Flour Sack is also about having fun as an animator, so the next time you animate him make sure it’s a joyful experience! That joy translates directly into the character and is what will make your flour sack animation really shine. Need some ideas for how to put the flour sack in action? Check out numbers 8-11 of the 51 Great Animation Exercises.