Table contrast ratio

Hello,

I have been working making some table designs accessible, as part of a wider UI kit.

My question is I have been looking at the WCAG guidelines for contrast ratio and how that might apply to the borders sitting between each row.

The nearest section in the WCAG guidelines I have found is for non-text contrast and interestingly talks about two things. If something is 'required to understand the content' then it looks like it needs to be 3:1. 'except when a particular presentation is essential'

The main issue I’ve found is 3:1 feels like it introduces a lot of visual noise and could makes it hard for the user to scan and absorb. As the tables I’m designing with mostly contain lots of clinically important medical data where the clarity of data is key, the focus for me needs to be on the cell content. I’m thinking in this case the lines can possibly be exempt from meeting 3:1 as they be described as  'except when a particular presentation is essential'

Is there a definitive guidelines around tables gridlines/cell borders needing to be 3:1, or is it secondary to the main focus of the data. And as such doesn’t need to meet 3:1?

Thanks,

Owen Sage
UX Designer
User Experience team