THIS page an overview of wool dyeing and eco printing
Unusual and rarely seen Catalpa Bignoniodes leaves are interesting: for one thing they are huge, so give a good coverage. They are hard to get colour from in emersion dyeing, because although they will dye pink-crimson, it oxidises to silver on silk and pale green on wool, so when eco printing on WOOL process I've added iron (dabbed on) which gives a dulled aubergine.
Modifying 'before' and 'after'
Catalpa leaves were dipped in iron water prior to placing on wool BEFORE steaming bundle. This helped to produce a colour; aubergine. Catalpa leaves were painted over in lemon juice AFTER steaming bundle. The latter result is encouraging, as there is a good deep pink. [This would be even stronger on Habotai. The wool is too fine loose weave for holding the strongest print].
It would be interesting to see what other leaves and plants stuff can be iron water treated BEFORE steaming, and lemon juice modified AFTER. I'm currently studying how to change colours of eco prints with the many and changeable effects of mordants and modifiers.