I'm definitely very glad that you picked up an ellipse guide after the first few of these. I know that students can sometimes feel discouraged given that we've dealt with ellipses so much thus far - but the way they're used in this sort of application is specifically difficult, because you end up with very specific ellipses all crammed together within a pretty tight space, not leaving much margin for error.

Eventually you'll be able to freehand them, but for now it's best to use tools that allow us to set aside the challenge of drawing ellipses (for which we have plenty of other exercises), and focus specifically on what is being practiced here.

As a whole, I'm quite pleased with how you've approached the construction of your wheels. They appear quite solid, and in most cases you're including that subtle widening through the midsection instead of sticking to completely simple cylinders. You're also paying a fair bit of attention to your spokes and rims, and have experimented with some especially complicated ones.

So, as far as construction goes, your work is solid. When it comes to capturing the tire tread textures however, you definitely have some weaknesses and points to address. I can see that throughout the challenge, you do experiment with different ways in which to employ larger areas of black. Early on, with the wheel on the top of this page, you've got a pretty severe miss - where you fill in the side planes of those spokes, you end up trying to employ form shading - something we specifically talk about avoiding in this course back in lesson 2. In this particular case, filling in side planes like this tends to separate the sides and front into graphic shapes, making them feel much more flat as a whole.

There are also other places where you try to use hatching, still falling into the pattern of form shading. It isn't until waaay at the end with this one that you start moving in the right direction. This isn't perfect, but the key thing here is that you're focusing more on drawing the shadows being cast by your textural forms, rather than drawing them explicitly using construction, or attempting to shade them. The reason there's room for improvement is largely that you drew those shadow shapes more in terms of creating a repeating pattern, rather than actually thinking about what kind of shadow each individual textural form would cast. As a result, we don't really get the impression that there are actual 3D forms there casting those shadows. It's a big step in the right direction however.

The key thing to remember - and all of this is explained back in lesson 2 - is that you can imply the presence of a 3D form without actually drawing it. Instead, you draw the impact it has on its surroundings - drawing the specific shadow shape it would cast. This requires us to focus on one form at a time, to think about how it relates to its surroundings, and then designing that specific shape. Each shadow is going to be a little different, though they may share many similarities. As soon as we fall into auto-pilot, trying to repeat the same pattern, the illusion fails. But if we focus on each form individually, it takes a lot more time, but the result is often better.

I like sharing the example of a bush viper's scales - it's not a tire tread, obviously, but it illustrates just how the shadows themselves relate to the forms in question, and how by adding more light, or taking that light away, we can impact how the texture is actually drawn without changing the nature of the forms that are present.

Anyway - this is pretty normal. Students have a tendency to forget about these specific things about texture, being so far removed from lesson 2, so I like to use the wheel challenge as a reminder. I'm still going to go ahead and mark this challenge as complete.