I have created a guitar pick with a cutout. I created this as a vector file in Illustrator. Then I imported the SVG file to Tinkercad and everything looked fine. The cutout shape appeared to be showing as empty. I opened the STL file in the Cubicon program so it could be set up for printing. In the Cubicon program, the empty space cut out of the pick also looked fine. However, when I print, the printer is filling in this space at the bottom. I can see that it recognized there is supposed to be a cutout, but the shape looks just like an indent and not an actual cutout when printed. I have printed other objects from Thingiverse that I did not create and didn't have this issue. Any ideas what I might be doing wrong? I do not have a base structure set to print, so that is not the issue.
3D printer filling in empty spaces (cutout areas)