Starting with the structural aspect of the challenge, while admittedly you've gone pretty hard and heavy on the detail to the point that it can at times be hard to distinguish between the underlying construction of the wheel and what was laid on top of it, there's enough here for me to see that you did indeed make solid use of your ellipse guides. While many of the wheels you drew were of the sort that are generally wider and more solid, you did include a fair few that get wider through the midsection, giving the impression that they're more inflated and that they'd land with a bounce rather than a heavy thunk - and leveraged your ellipses well to achieve that impression. I can also see that when drawing the spokes of your rims, you were mindful of both the outward face of those spokes, as well as the side faces of those structures - this is important because it helps to make those structures feel more solid and three dimensional, whereas some students will only draw the outward face, causing them to feel flatter and less tangible.

That said, I did notice that when constructing those rims, you ended up drifting away from the principles of markmaking from Lesson 1. This is to some extent understandable, since you're working within a very restricted, tiny space, but all the same it's important that you strive to adhere to the principles of the course even if it results in mistakes or other problems. At the end of the day, the things we draw here don't matter, nor does whether they come out looking good - what matters is that we're applying the process the course prescribes, and adhering to its core tenets, because it's that process which retrains our brains and our arms so that outside of the course, we can focus on what we want to draw, trusting that our subconscious brain can take care of the "how" by relying on the instincts and understanding we develop here.

All of which is to say that while adhering to the principles of markmaking we introduce in Lesson 1 may make your results here worse, that's not inherently a bad thing. If we modify the approach we use however to prioritize the result we get now, then we're lessening the long term value of the exercise.

Continuing onto the textural aspect of the challenge, this is admittedly something of a trap for students. Being as far removed as we are from Lesson 2 and all it discusses in regards to texture and the use of cast shadows to implicitly convey that texture, it's very common for students to either misremember how to approach the detail in their wheels, or to simply forget that there are specific approaches we should be using in this course. Students tend to fall into one of a few categories:

• Very rarely, students actually remember the implicit markmaking concepts and review them from the Lesson 2 material, and ultimately apply them correctly by focusing only on drawing the shadow shapes the textural forms would cast on their surroundings.

• The student remembers that there are textural concepts in Lesson 2, and that they involve filled areas of solid black, but don't necessarily review that material and end up working with filled black shapes more arbitrarily rather than following the specific methodology we prescribe.

• The student forgets about the textural concepts altogether, and either focuses entirely on drawing what they see, stroke by stroke, or employ constructional techniques to build up those forms as they would build any other construction - meaning, as though it's not texture at all.

For the most part it appears that you fell into the last category. I can see some use of filled areas of solid black, but it still seems to me that you're doing it based on observation (meaning, drawing what you're seeing), rather than observing your reference to identify the textural forms that are present, and using that understanding to decide what kinds of shadow shapes they would cast on their surroundings. While it's important for you to review the textural concepts as a whole, the reminders listed here are a good place to start, as they explain that we're not simply drawing what we see - we're using the reference image as a source of information, and then leveraging our understanding of the 3D spatial relationships between the textural forms and the surrounding surfaces to design our shadow shapes (rather than simply copying the shadow shapes we see in our reference).

The thing is, your wheels do look good - they're very, very detailed and you've clearly put a ton of work into them. But more specifically, they look good floating in the void, where they are the only thing around. If they were part of a larger illustration, all of that densely packed visual detail would create a focal point, drawing the viewer's eye whether you want it to or not, and interfering with your ability to control how the viewer experiences the illustration as a whole (which relates more to composition, and is outside of the scope of this course, but it speaks to why this can be an issue down the line).

Implicit markmaking - that is, implying the presence of those textural forms through the shapes of the shadows they cast gets us round this. Where working with explicit markmaking creates the expectation that everything you draw is present, and everything that has not been drawn is not present, implicit markmaking allows us to change the way in which we convey those forms without directly changing the information being shared.

As shown in this diagram, depending on how far the form is from the light source, the angle of the light rays will hit the object at shallower angles the farther away they are, resulting in the shadow itself being projected farther. This means that we can choose to convey a surface as being more densely detailed, or less densely detailed, and still have it tell the viewer that the same texture is present. It's not that the texture changes, but that its relationship with the light sources present does. We don't even have to worry a ton about maintaining full consistency with those light sources - it's just the fact that we can, when working with shadow shapes, have some forms cast larger shadows, and others smaller shadows, that gives us this control. From there, we're free to convey textured areas with very small (or even no shadows at all) - giving us a fairly low level of detail density, with very large shadows that merge together into complex, but singular shapes (again, low detail density), or somewhere in between where we get areas of shadow and areas of light that are more similar in scale (this is where we get the highest detail density).

Again - the key is that we get to choose, if we use implicit markmaking techniques.

The last thing I wanted to mention is that when it comes to those tires with shallow grooves, or really any texture consisting of holes, cracks, etc. it's very common for us to view these named things (the grooves, the cracks, etc.) as being the textural forms in question - but of course they're not forms at all. They're empty, negative space, and it's the structures that surround these empty spaces that are the actual forms for us to consider when designing the shadows they'll cast. This is demonstrated in this diagram. This doesn't always actually result in a different result at the end of the day, but as these are all exercises, how we think about them and how we come to that result is just as important - if not moreso.

Anyway, I'm still going to be marking this challenge as complete. The trap was very much intentional, and I find it is useful to remind students that sometimes things earlier in the course may have fallen through the cracks, and we might do well to reflect upon what else might have fallen through the cracks, so we can review it. You'll definitely want to review the textural concepts from Lesson 2, but take some time to consider whether anything else may have been left behind, so you can refresh your memory on it before continuing forward.