Well, if we're going to talk about the "z", then it's actually more like "ts" than "s".

In schwarz (black) may be but in zwölf (12)? Two different sounds surely?

Shvarts and Sssvulf. I wish I could do the old phonetics properly.

I think they are the same sound its just the stress is at the beginning of the word in both cases.

More like shvarsss and sssvulf then?

I'd always said shvarts.

Nope, it's the same. "Z" in German is pronounced "ts".

More like shvarsss and sssvulf then
I'd always said shvarts.
correct
and tssvelf I think nearer to an e than a u.
or between e and o.

Since I'm not likely to need to speak German again any time soon I shall wish you both ..

Gute nacht.

"Schvarts" is correct, as is "tsvoelf" (as far as you can use English sounds to describe the German pronunciations).

For added fun "Volks Wagen" is "Folks Vagen".

I must apologise to you Notary, reading back at my post to you I cringed. I'm sorry I didn't mean to come across as so aggressive.

Thats ok
We will see this week how the 'expert apprentices' buy their twelve or so products. How many shops they try before deciding. As I have already written I would find the price online before venturing. So far we know they paid £23 pound for a tartan metre which I consider a good price.