Pathfinder intersect tool not working accurately

[TomHolmes_G&I]

Never had this problem in years of using Illustrator, so assume it's another new bug.

If I draw one shape then another overlapping it, copy the rear item and paste-in-front, then select my duplicate and top shape – I should be able to hit the Intersect button and get a perfect shape of where the two items overlap. Instead I'm finding that this is no longer accurate, so I'm getting a slightly misaligned path, so the (pink) shape behind is showing through at the edges behind the front shape (blue).

Here's the result first at 'normal' size, and secondly when I zoom in. It's not even a consistent misalignment, is like it's just made a rough line that isn't the same. The match up is usually perfect, what's going on here?

[Monika Gause]

The circle in the back is still a live shape?

Try and convert it to a path.

Object > Shape > convert to path.

[TomHolmes_G&I]

It's just a standard circle drawn with the Ellipse Tool.

[Monika Gause]

The ellipse tool draws live shapes.

[TomHolmes_G&I]

If I draw a circle and go to Object>Shape the options are Convert to Shape (grey out) and Expand Shape. If I expand the shape it still has the same problem when intersecting.

I should add that doing intersects like this is part of my workflow for how I illustrate and I use this loads, it's not that I'm trying it for the first time or something. Never had this problem before, it's like something has changed and it's not 100% accurate since latest CC update. Straight lines seem to line up OK but on curves it's just that tiny but out that it leaves a load of messy edges when you zoom in.

Have looked at view as GPU vs view as CPU and problem persists. I can view results in outline mode and the pats are not aligned along any curved edges.

Would be good if someone could try replicating this in Illustrator CC 23.0.1 –

• draw a circle

• draw a square overlapping it in a different colour

• copy the circle and paste-in-front

• select circle and square

• intersect

• zoom in loads to check if curved edges are aligned

[Monika Gause · Accepted solution]

Next thing you could check is the pathfinder settings.

There is a setting for precision.

[TomHolmes_G&I]

Oooh, that seems to work, thank you. Was set to the default of 0.028pt and I've changed it to 0.001 which seems to be much better.

Still a mystery why this was always fine before now, but thanks for the workaround.

[Doug A Roberts]

I see what you mean, but I also see the same thing in CS6 and CC2018. Adjusting pathfinder precision mitigates it.