McAlpine Jugs

Can anyone tell me how many colours there are in McAlpine Jugs and what they are?

Hi Cushla and welcome to the site

Valerie Ringer Monk's Crown Lynn book shows 4 different McAlphine jug colours -
Blue, Green, Yellow and White.
You will find three of those colours in this Gallery on this site ....

http://newzealandpottery.forumotion.net/gallery/Crown-Lynn-Un-Numbered/Crown-Lynn-Un-Numbered-cat_c1.htm

I'm sure that I've seen Heather asking about a rumour that she heard that there is a Black McAlpine jug???

Yes, Ive also heard of a soft pink and orange

A guick google search and I found references to a pale blue and a dark pink ....

I have a McAlpine jug, in what I thought was a standard blue writing on white base.
(Not my thing normally but it was a very very cheap op-shop buy a couple of years ago.)
I've seen quite a few pass through trademe recently and thought they were all the same.
Maybe not. Val tells me mine is different from hers: mine a cornflower blue, hers more a turquoise. When I compare mine to the picture in her book I cannot distinguish a difference. It's so hard to be sure of colours in photos as it depends on lighting at the time of the photo.

Is anyone aware of more than one blue glaze being used on these jugs?

In glass-making salts of two metals are typically used to produce distinctly different blues:
cobalt (which gives its name to the glass colour) generally produces a dark-toned pure blue, and;
copper which makes a lighter colour, more turquoise.

I know nothing of the composition of glazes, but as the science behind colouration has remained much the same (for millenia) until the introduction of modern organic colours, is it possible that cobalt-based glazes were used on some McAlpine jugs and copper-based on others?

I read somewhere that these jugs were glazed in colour glaze colours....... ?
The colour glaze glazes were made from ceramic stains sourced from England and were sprayed on and then a clear glaze coat over the top.  Blue is the most desirable colour I believe as there are less to be found.

Check out google images for the different colours here -
https://www.google.co.nz/search?hl=en&site=imghp&tbm=isch&source=hp&biw=1366&bih=673&q=mcalpine+jug%2Bcrown+lynn&oq=mcalpine+jug%2Bcrown+lynn&gs_l=img.12...2839.18446.0.21765.27.7.1.19.20.0.254.1472.1j0j6.7.0....0...1ac.1.25.img..15.12.1282.3QjzZ1YxWOw