All the grids have even number of squares (equal black and white). Therefore it is impossible to start on white and end on white while covering everything else.

I don’t have the formal proof for this, but can be proven with examples. In each of your grids.

I’ll be following this thread to see if someone shares the formal proof for this, fingers crossed!

Ah yes… The pdfiles

Be like
✅ Seen

This one works. Thanks.

Dota Two… Is that you?

How do you add a line feed without a double enter?

I can confirm it exists.