The artist of our family is most definitely my step-daughter. As her skill and talent develop, she needs a true easel, rather than books propping up a canvas on the kitchen table.
The construction is a basic a-frame style easel. The center rail has a rabbet running down each side of it, forming a reverse t-track. This allows the bottom shelf and the top clamp to be adjustable for both height and various sizes canvases. The two movable parts lock in place with a couple of star knobs which essentially clamps them in place. The support leg is adjustable so that the easel can tilt at various angles. 
This is accomplished by using two lengths of wood, one of which has a through groove ran down most the length. The other has a knob to hold the two pieces together. A third piece links the to the lower length of wood and to the main a-frame of the easel. This makes for a very stable support leg.
I decided to keep the wood unfinished. This is because I honestly didn’t see the point of finishing it. With being used to paint on, it is going to get messy. Also, there is a good chance my daughter will want to paint it to make it her own. She is the artist after all! For this reason, I used poplar for the wood, both for the economy as well as it takes paint nicely.
This was a fun project to build! In addition to that, I am looking forward to seeing the wonderful works of art my daughter will create on it!