Do the drawings need to be completely symmetrical?
Does linear shaded fill mess things up?
There are several things to keep in mind when using vector drawing:
1) All shapes must be closed! Otherwise it is converted into a bmp image.
That means that any line you draw must connect back to its starting point.
Any shape you draw must be closed.
There is a "close shape" button in DP that you can use to close a shape.
2) If you use gradient shading, the image is turned into a bmp image and is no longer a vector image.
You must simulate shading using additional shapes of SOLID colors.
See my CTA Tutorials on the YouTube channel CTAStepByStep
Check out EZColors for CTA. The easy way to change Render Styled (RS) colors.