Congrats on completing the wheel challenge! I'll do my best to give you feedback so that you can improve.

Before I start on the challenge itself it's important to note that even if the ellipse template you have is bad it's still better to use it then to not. Because by using it you eliminate the need to think about doing clean lines and aligning ellipses to the minor axis and instead focus more on the wheels themselves.

Starting with the structural aspect of your wheels, you've done quite well. While freehanding certainly put you at a disadvantage (and I will always stress that the allowance of using an ellipse guide is not a kindness - it's to specifically help students focus all of their mental energy on the core focus of the exercise, without committing some of it to executing their ellipses as desired) you've largely handled it quite well. I'm pleased to see that you're mindful of achieving a curving profile to your wheels, which helps to capture the sense that the tire is inflated, rather than solid all the way through, and that it would land with a bounce rather than a solid heavy thunk. Though this is more so for the freehanded wheels as I can guess that the template limited you a lot which prevented you from achieving the inflated effect of the wheels. While this is unfortunate just be sure to draw your wheels more like 23 and 11 where the middle of the wheel is larger than the sides.

You've also handled the spokes of your rims quite well in most cases, establishing not only the outward face of the spokes but also their side planes, so as to establish them as solid forms. The only circumstance where I felt you fell a little short on there was with wheels like number 21 and 19. The rims are drawn flat because you failed to add a side face like you have on other wheels.

Continuing with the textural aspect of the challenge, you have fallen into the same trap that most students do at this stage, and it is largely by design. We are far enough removed from Lesson 2 that most students forget the principles of implicit and explicit mark-making, the use of cast shadows, and so on. This challenge serves as a good reminder that it is important to review that material before finishing up the course.

You use explicit mark-making to construct the protruding tire tread "chunks" in order to establish how they sit in space. You then go on to incorporate filled areas of solid black, but the opportunity to merely imply those textural forms has already passed once those forms have already been drawn. In addition, you usually fill in the side planes of those forms, which is more akin to form shading.

Explicit mark-making is not always an effective tool for every task because it locks us into a very dense amount of visual detail. This can be fine if we're looking at wheels floating in the void, but when we use them as part of a larger vehicle, they become focal points, drawing the viewer's eye to them whether we want them to or not. This severely limits our ability to guide the viewer's eyes through a piece.

Conversely, implicit mark-making allows us to alter how we convey the texture (in terms of how densely we pack in that information) without changing the nature of the texture itself, which we can see here on this example of bush viper scales.

Another point to consider, however, is that this can be pretty easily detected with very chunky textures, but when we're dealing with much shallower grooves, the distinction between doing it correctly and incorrectly can be pretty slight. Hell, the actual visual result can be the exact same, but the manner we think about it can make the difference.

When dealing with tires with shallow grooves - or any texture with holes in it - students can be prone to viewing the groove itself as being the "textural form" in question. So, they focus on drawing it, filling in the groove with black and moving on. But of course, the groove isn't a form - it's an absence of form. Instead, the forms in question are the walls along the sides of the groove, casting shadows upon one another, and upon the floor of the groove itself. This diagram demonstrates this concept visually, to make it somewhat easier to understand.

Lastly, here are a couple of additional diagrams - more focused on how we think through the texture analysis exercise in Lesson 2 - but still applicable here since it's all about understanding how to approach identifying our forms without drawing them, so we can imply them with cast shadows alone.

• Firstly, this diagram (or alternatively this one which is essentially the same, just framed a little differently in case it makes more sense) demonstrates how texture requires us to think about the relationship between the light source and each individual form.

• And secondly,this diagram shows, using a texture of melted wax, how we can think about first identifying the forms themselves, and then designing the shadows they'll cast.

• Additionally this diagram helps to differentiate between a cast shadow and form shadow which can help make the cast shadow notes make more sense

Anyway, I'll still be marking this challenge as complete. Just be sure to review the texture material, especially these notes. If you have any questions or are unsure about anything feel free to ask.

Good luck in lesson 7!