This test piece constists of 4 10x10mm squares at 100mm distance on the outside and one 10mm diameter circle in the dead middle.

Use this to calibrate your machines X and Y axis as well as ensure you have 200x200mm print bed by scaling it up by x2. You may wish to work your way up slightly changing the position of the center of the piece until you can print it at x2 scale and it maxing out the corners of your print bed.