Sorry for the longer-than-usual delay in getting you your feedback. We had some family visiting, and that made it tricky to find time to break away to handle my critiques.

Jumping right in, as a whole I think you're definitely heading in the right direction, and most of all I'm very pleased with the heavy emphasis on filled areas of solid black. I can see that for the most part you are thinking a great deal about how you're designing each shape, which serves a very important role in how we approach conveying these textures.

That said, the first point that I wanted to discuss pertains to the cases where your shadows get so small that you might feel that you can't go through the whole process of outlining the entirety of the shadow shape as explained here, and instead end up drawing your shadow as a single line. The thing with this is that lines drawn in that fashion will often struggle to taper off in a manner that is more natural, and so it'll feel like they end a little too thick. Obviously drawing shadows that small isn't going to be any easier as a shape that you then fill in, but in cases like this it may be better to let the smallest shadow you can manage drawing in this two-step process, designing the shape first, be the smallest shadow that shows up, with the next step being full white.

Continuing on, there was something I'd noticed that is best exemplified by the texture made up of lego bricks (number 22). There's actually two points I wanted to note regarding this texture, with the main one being that you appear to be thinking more in terms of the filled areas of solid black representing the planes of the lego bricks themselves (in the sense that you're effectively applying form shading, rather than defining the shadows those forms cast upon one another). Form shading is still a form of explicit markmaking, as opposed to cast shadows, which serve as implicit markmaking due to how they imply the presence of another form without ever drawing it directly. Our cast shadows may fall on other forms and wrap along their surfaces, but ultimately it still serves the purpose of implying the form you didn't draw as part of that step. Implicit markmaking is critical for conveying textures in the manner we explore in this course (outside of this course you can of course do it in a wide variety of ways), because it focuses back on the core principles of the course as a whole - defining the relationships between forms in 3D space. Those cast shadows, through the way in which they're designed, defines the relationship between the form casting it, and the surface receiving it, whereas form shading only defines a relationship between the position of the light source, and a single form at a time. It also helps us to learn how to control the density of detail we employ in a given area - explicit markmaking tends to lock us into drawing everything that we wish to convey as present, whereas with implicit markmaking we're able to convey the presence of much more, without drawing all of it.

As to the second point, this issue starts to get exaggerated where you've filled in planes facing towards the right side of your gradient, as this results in the overall light source being inconsistent. Be sure to always try and stick to a light source coming from the right, casting shadows towards the left.

Going back to the issue regarding focusing on cast shadows instead of form shading, this diagram may help, as a general breakdown of what we're thinking about as we approach each of these texture gradients.

• First in the traceover of the reference image, we're identifying the kinds of forms that are present and how they vary/how they're similar.

• Then in the first rectangle labeled "the forms we're transferring" this is more of an idea of how we would, in our heads, think about arranging those textural forms on our surface based on what we saw in the reference.

• Next in the rectangle labeled "how we're thinking about the cast shadows" are the actual lines we'd be drawing to design those cast shadow shapes, based on our understanding of the relationship between each textural form and the surfaces around it. The forms from the previous step are faded out here, because again - they weren't drawn. This is definitely the most challenging part, because working implicitly requires us to think about multiple forms simultaneously without drawing them - though not all at once, more a small handful including the one whose shadow you wish to design, and those whose surfaces that shadow might touch.

• And finally, we'd fill in those shadow shapes.

The last thing I wanted to mention is just some additional advice that doesn't relate too strongly to any one of your textures, but is still worth mentioning. When it comes to 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.

And with that, I'll go ahead and mark your challenge as complete. Keep up the good work.