Congratulations on completing the texture challenge! Looking over your work as a whole, I can definitely see a lot of growth and development of your understanding of the spatial relationships between the different forms and surfaces that make up each texture, and how they can be used to control the nature of the detail we use in our illustrations - specifically being able to control where our detail is at its densest (a lot of contrast packed into a small area, which creates a focal point and draws the eye), so that we are able to dictate how the viewer experiences a given drawing.

One of the main areas in which you've grown is in how much you've relied explicitly on cast shadows (which themselves define the relationship between a specific textural form and the surfaces around it) as the source of all of your textural marks. Earlier on, in cases like 7 and 8 on this page, there were definitely cases where you tried to create a transition through means that didn't require you to think about each mark in relation to the forms that cast those shadows - like stippling for instance. While these are easy approaches to create an arbitrary transition (similar to hatching), which while absolutely being a valid approach more broadly, are not the result of spatial relationships between forms, and so they don't work towards the role this exercise plays in the course as a whole.

Another way in which you visibly improved over the course of the challenge was in shifting more and more away from thinking of your textural forms as being distinct (similarly to how with the coffee beans on this page even to the far right you needed to outline each coffee bean in its entirety), shifting instead to thinking of all of the forms as essentially being structures along the same surface. This is something we can lean into more easily with textures like the ground beef on the same page, since there aren't distinct objects that your brain is going to feel compelled to outline distinctly - but as we get further into the set, with the corn and scales towards the end you've started applying the same kind of thinking from the ground beef to textures that would be more prone to being viewed as distinct items. All of which is to say, you've definitely broken down that need to approach everything with explicit markmaking, and so the way in which you think about these textures has developed well towards engaging with them more through implicit markmaking.

Now one issue I did notice is that you appear to be dictating the direction of your cast shadows based on your reference, which is incorrect. The only thing that the reference dictates is the nature of, and general arrangement of, the forms that make up the texture. Everything else including the position of the light source - and within reason, even aspects to how the forms are arranged - is in your control. The gradient itself is meant to be arranged such that the light source is on the far right as discussed here.

This arrangement is a big part of how we are able to achieve the gradients. I believe I shared this with you in your wheel challenge feedback, but it doesn't hurt to share it again - as shown in this diagram, the further from the light source the textural form is, the longer the shadow it casts will be, due to the shallower angle at which the light hits it. So as a natural result of this, the further we go to the left, the longer those cast shadows will be, resulting in more of those forms' shadows combining into large, complex shadow shapes that engulf the far left of the gradient.

Since every mark we put down is a cast shadow, that does also mean that we can't simply fill areas in without considering the spatial relationships involved. For example, on this page you've got seeds that tend to sit inside of a bit of a depression, and you filled those depressions in with solid black in most cases. That's not an assumption we can make by default - though much further to the left, it's likely that the shadow cast by the right edge of the depression would fill the depression in its entirety, further to the right side of the gradient you're going to have much smaller shadows that don't cover the whole thing as we see here. There I've illustrated how the surfaces are higher around the depression, lower within the depression, and higher on the seed - and how that results in the far right edge of the depression casting a shadow into it, but not actually covering the whole thing. This results in a section of the depression along the left that does not receive a shadow at all. You'll find more detail on this point here.

The last thing I wanted to briefly discuss is the gradient for your last texture, the scales on this page. Overall this is definitely well done, but the jump to solid black on the far left is a little abrupt, since we're jumping from relatively small shadows to a huge one right at the end. Instead, having the cast shadow increase gradually over the whole thing is going to give you a far better result as shown here.

Anyway, all in all you've definitely made some solid progress, but be sure to keep the points I've raised here in mind. I'll go ahead and mark this challenge as complete.