Hi, So I have fixed the problem for me, however this is a document that will be downloaded by other people, is there a way of saving the preferences on the doc, meaning by default that the enhance thin lines box is unticked when people open it?
Thanks
"is there a way of saving the preferences on the doc"
No. This is a viewer-related issue. It has to be set by the end user.
It's also an Acrobat-specific issue with the "Enhanced Thin Lines" option. Other viewers are not affected by it. It also doesn't affect print quality.
The issue is how the PDF file format handles simple rectangles in compressing the file.
When you convert a font to outline, sanserif letters like a lower-case "L" or capital "I", become simple rectangles. Simple rectangles can be compressed in a way that makes them actually behave, in a way, like strokes. This saves coding space, making the file smaller. Acrobat's viewer sees them as strokes, and hence the "Enhance Thin Lines" option can affect them... potentially making these "strokes" a bit bolder compared to other letters beside them, depending on the viewing percentage. Turning off the "Enhanced Thin Lines" eliminates this issue by having everything rendered similarly.