Backplate PDF does not match spheres.stl

[Chandler]

I'm using an assumption of 300 DPI for the backplate PDF. These are the units used when opening it in photoshop

When I compare spheres.stl in the same units to the backplate image I find that the registration holes do not line up.

Here is a rendered image of spheres.stl over the backplate PDF showing that the registration holes are not at the same scale

I've found the same holds in the real world, the 3D printed object holes do not match an inkjet printed version of the backplate at 300 DPI.

Do you have any hints? Am I using the wrong scale for the backplate.

[Chandler]

I think I found the issue, photoshop by default opens the PDF cropped to the "bounding box" which obviously ruins the units ;_;

If I change it to crop to media box I get units that match up with the 3D model

[mprat]

@Chandler nice find!

Do you want to send a PR against the README that maybe explains this better? Where would you have looked for this info to find it?