hello block is pretty I have a tip for you when making half sq triangles use a mechical pencil. I don't know what ruler you are using to mark your blocks I us the ruler that has a slit in the center it is made for the hst. you just put the ruler from corner you an mark on both sides of the ruler very easy. then just sew each side a needles width to the right of the pencil line slide the block around to the other side do the same thing then you cut do the center and have two half sq triangles