Closely related to the enveloping schema, but with its own distinct character, the enveloping schema is about creating boundaries.
Does your daughter like to create enclosures for her toys? A farm fence made from blocks or string?
Perhaps your son enjoys drawing circles, looping the line around smaller marks already on the page.
At first glance, the enclosing schema seems very similar to enveloping (no. 83 in the 100). Both involve closing around something, but that's where the similarity ends.
Whereas enveloping wraps an object, often removing it from sight, enclosing simply contains it. It's the difference between a doll bundled up in blankets and a horse in a paddock.
Enclosers likes to draw faces, placing the eyes and mouth inside, hair and ears outisde. An enveloper's drawings, on the other hand, focus on making things disappear. They might draw a pretty scene only to obliterate it completely with paint, covering the entire page with a single colour. Nothing of the original remains.
When children enclose, they are learning that objects - or ideas - can be contained in a discrete space. And that anything outside this is a separate entity.
Envelopers explore how objects can disappear but still exist (see the blog for more on the idea of object permanence).
Eventually, enclosing leads to letter-formation. The balled fist that first holds a crayon, making endless spirals on the page eventually becomes the dextrous hand drawing circles for 'o' and 'p' and 'd'.
It's also central to drawing faces and bodies. Leave a gap and there's a space for the colouring-in to leak out.
Like all schema play, development of the enclosing schema happens naturally. But if you know to look out for it, you can provide opportunities to practice and improve.
So much of early years education - and the 100 Toys approach - is about noticing. Take the time to observe and reflect. It's not rocket science. But the benefits of a thoughtful intervention can be huge, helping your child to make connections and deepen her understanding.