Yo, TA qzhans here!

Before we begin, I just want to congratulate you on giving those 250 boxes a good ol’ pen and ink smackdown. It is a MASSIVE undertaking and you’ve joined the prestiged club of its completers. And you even did an extra 50 to boot!

You’ve painstakingly drawn through all your boxes and extended every single last line out to check your errors, and your boxes have been better for it. Indeed, you’ve made a marked improvement throughout the set.

In general, I like your linework. There was a lot of sketchy, re-drawn lines in your first 250, but you seemed to have fixed that in your last 50. I like how you don't try to fix your lines, working around them even if it means making a wonky box. The next challenge when you pull this out for warm-ups would be to experiment with line weight, reinforcing the silhouette with a confident line to help the boxes pop.

However, I feel like your internal understanding of convergence still needs an extra push somewhere. The thing about boxes is that we're actually tricked fairly easily; as long as the front facing lines all look like they converge properly, even if it goes wonky in the back, we'll still be convinced. Thus, what I like doing is drawing the 3 lines (forming a "Y") from the corner that's closest to us, then dealing with the visible edges (2 per branch of that "Y") and making sure they are properly converging towards a shared vanishing point. Then, only after that do I pick a far corner in the back and finish the box with the drawn-through, "unseen" lines (not sure if this is what you were doing already, however). This ensures that the visible edges are properly finished.

I can also offer this advice. When you go to draw a line, think only about the lines that are supposed to be parallel to it (share a vanishing point). Lines closer to an existing line will converge slower, while the opposite is true for lines further away. Also, don't be afraid to plot some dots down on the page first, just to kind of imagine how it will look. This will help you catch a lot of convergence mistakes earlier, and the dots will be ignored even if you put a few of them down.

This issue showed itself the most when you tried more isometric boxes. if you find yourself struggling with divergences, it can help to go back to more obviously converging ones.

Overall, I'm thinking you're almost ready for Lesson 2, you just need a bit more to really help solidify this fundamental knowledge. Thus, I'm assigning you 10 more boxes. Try to do most of these as subtly converging ones, but if you're having trouble switch back to more distorted, obviously converging ones. Really try and get the convergence as tidy as possible this time.