Holes in top layer

Hi all - I’m fairly new to printing but one thing I have started to see in my prints is small holes in the topmost horizontal surfaces. The holes are appearing above the voids in the infill pattern - it’s like the air in the infill voids is expanding as the top layer is printing and popping through that top layer

I’ve attached an image to show what I’m talking about - I’ve seen this on several prints now

Sliced in Simplify 3D - tried in both High quality and Medium quality profiles 30 and 20% infill - same issue comes up
Printing on Taz 5 - IC3D 3mm ABS filament
Bed@90F and Nozzle@230F
Printing in an enclosure

Any tips much appreciated

How many top solid layers are you printing?

Set to 3 layers

The curve transition could be confusing S3D. Post to the S3D forums. How does the part look in the preview print?

Thanks folks - after some experimenting, I just needed to up the number of top layers

As a general rule, the lower the infill the more top layers you need.