No gaps in shell of STL but when sliced in Cura 5, there are gaps

I have created a stamp in cookiecad which looks great in cookiecad designer. However, when I pull it into Cura 5.0 and slice it, there are gaps in it. What settings would you recommend to eliminate those gaps?

The reason is that the lines are too thin to print with your nozzle. To fix it you can either increase the line thickness in the original image, or you can use experimental settings → thicken interior. I find adding 0.3 mm in thicken interior usually resolves this.

This is a great idea - you can also try turning on the ‘print thin walls’ setting, but just know that if they’re not showing up in the slicer, and you force them to print, they may be brittle because the nozzle has to under-extrude to get those lines in. Might be fine for what you’re doing though, so give it a try! Also possibly try “horizontal expansion” by a tiny bit, however it does this to the whole model.

One thing to add - I also updated to Cura 5 recently, and immediately went back to Cura 4 because I started having weird wall gap issues, so maybe try the latest version 4 if all else fails.

What is the thickness of your blade?