Studio Cut, a 6x6 Patches puzzle
Arrow keys move. Enter starts a rectangle; arrows resize it; Enter places it. Escape cancels. Delete removes a patch. Control or Command Z undoes.
About this board
A 12 dominates the left side, and it is the only patch fixed from the start: a 4x3 block through the middle rows. Around it the board cuts cleanly into strips, a 4 on top, a wide 4 below and a 6 along the floor, while two shape-only clues on the right, a square and a tall rectangle, take what's left of that edge.