Printing HF RFID Antenna Layout for PCB Fabrication

Hello everyone,
I have designed a HF RFID antenna which I'm going to build. Long story short, I have a spiral with 1mm wide tracks and 1mm gaps in between the tracks. And I wish to print the layout in order to implement my PCB from it.

I have drawn the spiral using AutoCAD and Altium. I have made sure the width of the tracks equals the width of the gaps. But every time I try to print the pattern, the proportion is automatically changed and the width of the tracks appears to be larger than the width of the gaps. I get the same problem with both AutoCAD and Altium.

I think AutoCAD adds and outline to my tracks, which I can't get rid of. I have no idea why I also get the same problem using Altium. It's not a problem with my printer, as I get the same result when I create a PDF model of the layout.

Any ideas/suggestions would be greatly appreciated. Thanks!

I use Altium a lot and I never seem to have the width/gap modified. I have never done any microstrip (PCB based) antenna, but if you are using tracks they will turn rounded at the endings and every antenna of that kind I have ever seen are all rectangular. I would recommend you to use "polygon" or "fill" paths.

When using Altium, at print preview, always remember to go to "page configuration" and keep the "scale" value at 1.


EDIT: Wrongly read "RF antenna", RFID antennas do have rounded corners.