h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Currently trying to sew together a republican 'Toga Praetexta' -- the type of toga carried by consulares -- the senators that had been or currently were consules. The _toga_ part isn't the bad thing, that's practically a white sheet of cloth, some 4x4 meters big. The bad part is the wide purple ribbon that is to be sewn onto the circular part of the toga. Some five meters of purple 'ribbon' out of a silk-like cloth to be torn into 30cm-wide strips , wrapped around the toga-cloth, and sewn into place. It's quite a chore

Any tips on how to tie a toga, out of a large piece of material (not a sheet, I've been told they're not good)?
Any thoughts appreciated.