Well, I bought some Alum on special order from a local chemists as nowhere seems to stock it locally. When it arrived it looked unlike the Alum I'd seen on the web - not white powder at all - but like tiny clear granules. I was worried then... what if it wasn't the right thing? Did I really want to go boiling this stuff up when it might have disasterous consequences?
A quick question posed on a science forum thankfully allayed my fears - the stuff I have is the same, but it's been purified to reach European standards, hence the clarity. I can mordant at the weekend with confidence! (I hope)
I won't go recommending it to anyone until I can show my results though.
The weather remains cold and drizzly on the Island, and I feel like I'm definitely coming down with a cold. Curses....... Just when I thought I'd avoided all the plagues of lurgy that had been going around at work. That's air conditioning for you. THERE IS NO ESCAPE. The most unhealthy environment for human beings - ever. Pah!
In my old office, with old-fashioned radiators and windows that you could open for fresh air, I survived month after month without falling prey to any germs.