The paper note stretches when I try to align in by size. I tried adding separating the notes object in a single note and all of the Texture coordinates options, is there a way to avoid stretching.
Yes as Martin and Omar says, make sure the UV's are correct. Trying to adjust the mapping node scale and location is not going to work if the UV's are incorrect.
When using the UV texture coordinates, the UV's need to be correctly aligned with the image in the UV editor.
Also you may need to apply the scale, this can cause stretching if the scale is not correct.
