Doing these studies was harder than I thought. While I don’t really like any of these models, I tried to make each study focus on either folding paper [Model 1], cutting and interweaving paper [Model 2], or cutting and arranging paper pieces [Model 3].
Model 1, View 1 
Model 1, View 2 
Model 1, View 3 
Model 2, View 1 
Model 2, View 2 
Model 2, View 3 
Model 2, View 4 
Model 3, View 1 
Model 3, View 2 
Model 3, View 3 
Model 3, View 4 
Model 3, View 5 
Model 3, View 6 
Model 3, View 7 
Model 3, View 8
I think that using the black construction paper helps highlight shadows and creates a nice contrast. It’s cool that in model one you ripped the paper because it adds texture to the piece but it may strengthen the piece to still have some crisp edges.
I love the usage of black construction paper in this piece. Like Stasia said it does create beautiful shadows, highlights, and contrast. I wonder how it would’ve looked if you maybe included one color and played around with the contrast of that.