Looking over your submission, overall you're heading in the right direction, but there are a couple points I feel I can call out to help you continue to progress and ensure that your focus is on the right areas. The issues I'm going to call out fall into a few specific categories, which we'll talk about one by one:

• Cast Shadow vs. Form Shading

• Branching Tubes

• "Negative Space" Textures

• Smooth Gradient Transition

Cast shadow vs. Form Shading

There were definitely a lot of places throughout your work where I was a little on the fence about whether the marks you were drawing were meant to represent the shadows cast by your textural forms, or whether they were more a case of applying form shading to the textural forms themselves. The main difference here is that form shading pertains to when we take a single form and, based on which of its surfaces point towards the light source and which point away from it, cast shadows involve a form casting the shadow, and the surface receiving it, with the shape of the shadow itself representing the relationship between those two elements in 3D space.

To go into a bit more detail,

• Shading involves filling the form's surfaces in with some tone from black to white. Normally there would be greys in between, but our range jumps straight from black to white, leaving us with black for the surfaces pointing at all away from the light source, and white for those surfaces pointing more towards the light source.

• Cast shadows involve one form blocking the light from reaching another surface, causing a shape to be projected onto that receiving surface.

Now, for the context of this exercise (and the course as a whole), form shading is a form of explicit markmaking, because it requires us to draw the forms themselves, whereas cast shadows is a form of implicit markmaking (because the form casting the shadow does not itself have to be drawn, just the shadow it's casting). Implicit markmaking is important here because cast shadows can vary in their length. In one spot you might have smaller shadows, or even no shadows, and in another spot you might have large or deep shadows that extend much further from the form casting it. This variation means that we can control where we want to include more detail, and where we want to include less, allowing us to control which parts of our drawings pull the viewer's eye.

This idea of cast shadows of different sizes is demonstrated here, which illustrates the same kind of texture analysis gradient arrangement, but viewed from the side rather than the top. The textural forms closer to the light source on the right will receive the light rays at a very sharp angle, resulting in a smaller cast shadow. The textural forms much further away from it to the left receive the light rays at a shallower angle, causing their shadows to extend considerably further. This provides us with a tool we can use to leverage control on how we can go about conveying information.

If we could only work with explicit markmaking - whether it's by applying form shading to these textural forms or by outlining/constructing each textural form - we would basically be forced to draw each and every textural form in its entirety, lest it not be regarded as being present. Either you draw it and it's there, or you didn't draw it, and it was never present. With cast shadows however, you can create the impression that a texture covers an entire surface, while only drawing it in key areas. This means you can convey the presence of that texture, without having to pack your drawing full of noisy detail.

Using texture 20 on this page as an example, I think this is the case where I felt most confident that you may have intended to fill in the side planes of the textural forms (in other words, using form shading), but to be honest I'm still not 100% sure if that's the case. There's definitely still leeway here to suggest that you were intending to work with cast shadows, so instead of saying what you did or didn't do, we can talk about how they would differ from one another, so that regardless of whether you were doing it right or wrong, you can walk away with something useful.

Here's my analysis of one of the forms from that texture (as circled in section A). We can interpret the actual textural form being conveyed here either as B (where the filled area are the side planes, so that would be explicit markmaking rather than implicit), or as shown in E (where the form exists beside the filled black shapes, with those shapes being the shadow the form casts on its surroundings).

If your intent was the latter, then you're approaching it correctly (albeit with room to improve the specificity of how the shadow is designed, but that is by no means abnormal). If it was the former, then C and D demonstrate what the correct cast shadow shape would have been in this context.

One last thing on this point - these notes from Lesson 2 talk about what we're actually doing as we pull information from the reference image.

Branching Tubes

My feedback's already getting pretty long, so I'm going to try and touch upon these remaining points more briefly. This one relates to texture 21, which appears to be the veins of a leaf. The issue here is that you're drawing the tubes of the veins one at a time, which results in problems where you have to have a new vein branch off an existing one, but its outline is already in place, as we can see here. This kind of problem is inevitable if we approach the texture by drawing each vein one at a time.

Instead, if you focus on outlining the areas where the branching actually occurs, as shown here, you can build those up first, before committing to any longer edges that might block other areas off. Once these branching sections are all figured out, you can worry about which edges should also be casting shadows. You can see an example of this in Lesson 3's leaf exercise diagram.

"Negative Space" Textures

A lot of textures have names that speak to the actual textural forms in question (a brick texture, a scaley texture, a bumpy texture, etc.) but there are other textures that speak to the absence of form - like holes, grooves, cracks, etc. - and this use of language can result in confusion for students in terms of how to go about drawing those textures. If the name refers to the absence of form, then students will often default to attempting to drawing that named thing directly, which tends to result in a lot of explicit markmaking.

This is present in a number of places in your work, although one of the more prominent is the cracked tree stump on this page. Because "cracks" were on your mind, what you did was fill in the cracks that were drawn. This unfortunately doesn't allow us to consider how the forms that make up those cracks exist in 3D space, and so the resulting texture comes out looking quite flat.

Instead of focusing on the cracks themselves, we need to think about the walls that surround those empty spaces, and how they exist in space. The marks we draw are the shadows they cast upon one another, as explained further in this diagram.

Smooth Gradient Transition

This last point is simply a part of the instructions you appear to have missed. When drawing the gradient portion of the exercise, we place a solid black bar on the left, and we leave a similar bar on the far right empty. These represent the black and white extremes, which as explained here in the instructions, our actual texture (and all of the cast shadow shapes it is comprised of) serves to link together in a seamless gradient from dark to light.

It appears that in your textures, you were not as aware of the need to blend the black bar seamlessly into the texture, and so yours pretty much all have a very clear and obvious hard edge. When doing this exercise in the future, be sure to focus on eliminating that clear edge - it will require you to expand your cast shadows more as the forms casting them move further away from the light source, and that may feel a little unnatural, but it is something you'll get used to.

And with that, I'll go ahead and mark this challenge as complete. You're headed in the right direction, but hopefully I've been able to highlight a number of points for you to continue working at.