A parametric, 3 leaf, shamrock script.

Planar does not fully fill up the interior of the curve, near the center.
Boolean and Trim do not seem to work in that area.
Tried MoI 4 and MoI 5 beta.

Placing a circle at the center, with radius greater than the planar problem area, enabled multiple trims of the narrow areas near the center of the shamrock.
Blend was then done, and join. Now planar worked for the entire revised inner area of the curve.

Still need a stem...

- Brian