Our latest One Hour Design Challenge, Ideation Sketches, closes in only three days. The entries continue to roll in, but we wanted to make sure all of you had an opportunity to show of your sketching chops. This is your final reminder! Enter Now!

In case you missed the announcement, the brief is simple: Make as many ideation sketches as you can in one hour. Entries will be judged on design excellence, focusing on form variation, sketch quality and composition.

Finally, don't be afraid to enter just because you aren't well versed in traditional methods of thumbnail sketching. This competition is about ideation and quality—the more variety in sketching style, the better. We love the immediacy of Madeleine_AR's sketches (below): despite her iffy relationship with perspective, her forms vary widely and evoke a very particular Martino Gamper/Royal Tenenbaums quality.