Starting with your organic forms with contour lines, it's clear that you're definitely trying to stick to the characteristics of simple sausages, but yours are coming out quite stiff - primarily because you're going out of your way to keep many of them very straight, instead of letting them curve more fluidly. There's also a tendency to have the ends stretch out a little bit at times.

While along the top of the first page, you drew that little thing with your ellipses changing in degree, showing that you understand that the contour ellipse should be getting narrower/wider as you slide along the length of the form, I think you're actually getting the direction of the shift backwards in a number of cases, and in a few others, you end up forgetting to have them shift at all.

Right now, you're having those contour lines get wider as they get closer to the viewer - this is incorrect. Closer to the viewer they'll be narrower, and as they slide away, they'll get wider. You can see this demonstrated in the lesson 1 ellipses video.

Don't forget to draw through all of your ellipses two full times before lifting your pen, as well.

Continuing onto your insect constructions, there's definitely a lot of good here, along with a few issues to address. There are a lot of drawings where you're doing a good job of building things up through the addition of individual, simple forms, working your way up to greater complexity by adding more rather than making the individual components you add more complex. So for example, this ant's body comes together quite nicely - the segmentation along its thorax area, and the bulbous form of its abdomen all come together nicely.

There is however a bit of an issue in how in some areas you do appear to trace back over your existing linework. For example, we can see this quite prominently in the abdominal mass, where you started with an ellipse that you drew through nicely, but then you went back over it with a darker, thicker line. In doing so, however, because you were trying to go back over so much, you had to draw more slowly and hesitantly, introducing little bits of complexity to that otherwise smooth ellipse, and ultimately redefining the silhouette of this form you'd already constructed.

Because we're drawing on a flat piece of paper, we have a lot of freedom to make whatever marks we choose - it just so happens that the majority of those marks will contradict the illusion you're trying to create and remind the viewer that they're just looking at a series of lines on a flat piece of paper. In order to avoid this and stick only to the marks that reinforce the illusion we're creating, we can force ourselves to adhere to certain rules as we build up our constructions. Rules that respect the solidity of our construction.

For example - once you've put a form down on the page, do not attempt to alter its silhouette. Its silhouette is just a shape on the page which represents the form we're drawing, but its connection to that form is entirely based on its current shape. If you change that shape, you won't alter the form it represents - you'll just break the connection, leaving yourself with a flat shape. We can see this most easily in this example of what happens when we cut back into the silhouette of a form.

Now this is something a lot of students do intentionally, taking shortcuts to quickly refine their forms. While you ended up doing it mostly when trying to add line weight, it also came up in cases like this beetle's horns, where you introduced a complex, flat shape rather than building it up gradually.

Instead, whenever we want to build upon our construction or change something, we can do so by introducing new 3D forms to the structure, and by establishing how those forms either connect or relate to what's already present in our 3D scene. We can do this either by defining the intersection between them with contour lines (like in lesson 2's form intersections exercise), or by wrapping the silhouette of the new form around the existing structure as shown here.

You can see this in practice in this beetle horn demo, as well as in this ant head demo. This is all part of accepting that everything we draw is 3D, and therefore needs to be treated as such in order for the viewer to believe in that lie.

Now, when it comes to line weight, there's no need to try to apply it all over the place, or in an arbitrary fashion. Line weight follows specific rules - we use it only in specific, localized areas to help clarify how certain forms overlap one another. We keep it limited to those small areas to avoid tracing hesitantly (tracing tends to focus too much on how our lines sit on the flat page, rather than how they represent edges moving through 3D space), so we want to avoid that and focus on using the ghosting method to execute those marks with confidence. This will also help it blend more seamlessly into the existing linework, as you can see in this example.

The last point I wanted to call out just comes down to the fact that you've gotten somewhat misguided in where your time should really be invested in this course. It's really clear that when you got into the detailed drawings, you ended up focusing a lot on the idea of "decorating" your work. That is, to do what you could to make those images look more interesting and impressive. In some cases, you did a good job - the dragonfly ended up looking quite nice - but as a whole, this is not what we're meant to be focusing on in this course.

What we're doing in this course can be broken into two distinct sections - construction and texture - and they both focus on the same concept. With construction we're communicating to the viewer what they need to know to understand how they might manipulate this object with their hands, were it in front of them. With texture, we're communicating to the viewer what they need to know to understand what it'd feel like to run their fingers over the object's various surfaces. Both of these focus on communicating three dimensional information. Both sections have specific jobs to accomplish, and none of it has to do with making the drawing look nice.

So in this regard, there are a few things to remember. For example, in lesson 2, we talked about how form shading would not play a role in the drawings we do for this course. So the hatching you added to your praying mantis should not have been there. Also, there's no need to try to capture any local/surface colour - for example, where you filled in all the black areas on your bee to capture the areas of the bee itself that were indeed black. Since we wouldn't do that for any of the yellow sections, there's no reason to treat black or dark areas as some kind of special case.

This actually ends up confusing the viewer - instead, it's best to reserve areas of filled, solid black, only to capture actual cast shadows. When it comes to local colour, we can treat everything like it's covered in the same white surface.

Now, there are a lot of things to keep in mind here, but as a whole I think they all can continue to be addressed as you move into the next lesson. I think your overall grasp of construction is coming along well enough, so I'm going to go ahead and mark this lesson as complete.