There are many benefits to giving children an opportunity to work on a vertical surface like an easel. Here are some examples of how working on a vertical surface can benefit young children:

• develops shoulder stability
• opportunities to practice crossing the midline (ie: making large markings that stretch from one side of the body to the other)
• develops core strength
• allow kids freedom to move while working (as opposed to being seated in a chair)
• provides opportunity for coordinating both sides of the body (think: using one hand to hold a stencil and the other to trace)

Not everyone has space for a typical easel in their program. (Not to mention an easel can be a limiting tool to begin with!) Here are some ideas for easel substitutions:

• Pick an open wall in your classroom and attach a piece of plexiglass to it. Use tape to hold paper up for painting projects, or give your kids dry erase markers to draw directly on the surface.
• Don't have a wall you can use? Use the back of a shelf or other piece of furniture instead. If you have a shelf that is facing away from the wall with a blank side exposed, use that to be your easel. If you're concerned about protecting the item, attach plexiglass to it. If you're not, go ahead and attach paper directly to it for your kids to paint on.
• Use your yard fence instead. Tape paper to the wood and invite kids to use that as their easel.
• If mess is a consideration, instead of permanent art projects and paints that stain, use buckets of water and paintbrushes to paint the fence (and other outdoor items). The bonus is that it will dry and your kids can do it again and again and again--minimal materials required!

Perhaps after reading this it feels easier to just go out and buy an easel or two. If so, Ikea has a very affordable option.