sweep node, spiral / wrap a curve around a curve

 I always forget how to do this ,so here we are.
This creates a spiral loop around a provided curve (no need to add cross section)
Important bits - Round Tube surface shape, Columns surface type, control the twists in the rotation section.

random vellum rest length in houdini core

 To randomise the stretch rest length value on initialisation (not dynamic, it can't be animated like this). make a primitive wrangle between the vellum hair constraint and the solver.

I've used a connectivity node set to Primitives and changed the "class" attrib to "hairID". Here we affect the restlength value by multiplying it by some remapped randomness.

f@restlength*=fit01(chramp("remap",rand(@hairID)),chf("min"),chf("max"));