Topic: Early Mdina cobalt blue sidestripe button rim

[flying free]

The two pieces I have that have cobalt in them are both I believe, very early (in the life of Mdina) pieces, not just because of the cobalt but because of the style of the design.

Mark Hill says clearly that cobalt oxide was added to the batch :
On page 21 it says ' two batches of clear, colourless soda lime glass were melted in separate furnaces. Metal oxides, such as cobalt oxide, were added to one batch which gave colour, in this case a deep cobalt blue.  A gather of glass was then extracted from the coloured batch and rolled in chemicals to modify or change the colour, and add others.

m

[chopin-liszt]

Yes, found it.
But while it might be implied that this was in '68, it doesn't actually specify that, does it?
It is delightfully vague.

But if you turn over to p.22, it gets a bit better.

(some colours such as an amethyst) "purple or cobalt blue in its unmodified form were only used as final colours for a short period of time in the first year of production".

Does that refer to the non addition of salts, so just the small Fish (and perhaps a few one-offs) really?

It doesn't tell us much about its use in modified forms with salts and other colours.

[flying free]

Further confusing information for cobalt appears on page 32.  I refer to this comment later, but firstly,

I think what we need to know is what exactly Mark Hill means by my underlined
 'purple or cobalt blue in its unmodified form were only used as final colours...'

and   
'purple or cobalt blue in its unmodified form were only used as final colours ...'

And specifically I want to know because my sidestripe is cobalt and lots of it, and I'm sure it's an early Michael Harris piece.  I suspect it might be an example of both those underlined comments, because the cobalt hasn't been rolled in any chlorides or mixed with any,  it is pure cobalt on the outside.  The interior I believe was a clear rolled in chlorides and then cased over in a final unmodified colour cobalt blue

As I say, on page 32 (under chapter of fish vases) there is further information -
'Colour and patterning also vary widely, with each example again being unique.  The green used on other ranges is more commonly seen, (my words- when he says green, I suspect he means turquoise?)as is the very deep purple colour associated with pieces produced during MIchael's ownership of the studio.  Both can have added streaks or swirls of deeper colour under the clear casing,or take on a mottled cloudy appearance.  The purple itself can appear to have a brown tinge when light passes through it,  or appear as a royal blue when light is shone onto the surface. Silver chloride escaping from the area where the glassblower's rod is attached to the piece (the moil) can add an iridescent swirl.  Other coloured enamels were also applied to the surface of the internal body, such as sandy yellow, cobalt blue or brown in random swirling or mottled patterns. These can often look as though they have been 'painted' onto the body in an abstract manner.'

To demonstrate this point above, on page 34 there  are two  very large sculptures made by and signed by Michael Harris and dated to c.1970  I think they both contain cobalt blue swirls in them, with one being mostly turquoise blue and the other being mostly the bright 'teal 'y' turquoise blue.  The effect is the same as the cobalt blue in the wings on my fish vase
There is only one other piece in the book that I think might contain cobalt and that is the fish on page 31 that is labelled as cobalt blue Fish.  I think it might have cobalt in the wings but I don't think the whole fish is cobalt 

So it's possible that if Cobalt was only used at all in the first year of production, then these are wrongly dated if they contain cobalt swirls, and should date to c. late summer 1968-late summer 1969.
However, if cobalt was used as a final colour only within the first year but also used in later years  within the swirls of a piece, then they could of course date to c.1970 (if indeed they do contain cobalt).
 That is a plausible explanation for cobalt use because I think it was expensive?  so using it in small quantities as a decorative effect may have been a cost efficient way of still being able to use it? 
Perhaps that's how the whole 'swirly' Mdina effect came about?  a way of ekeing out expensive colours, making them look stunning but cost efficient by using a clear base.
 It's also possible that the 'solid' colour effect of one colour all over the piece, was not a design or aesthetic effect he was looking for in his range.

m

[chopin-liszt]

Can I have a few hours to try to digest what you're saying, m?
(My swiss cheese brain has trouble with embedded clauses.  )

[flying free]

 
just one short comment more -

- my fish is exactly  the same colours as the Sculpture on page 35.  It is that bright turquoisy teal with the cobalt blue swirls in the wings only. (mine has no amethyst or chlorides in though).

m

[rosieposie]

Hello m at the start of this long thread, you mentioned that there was a curious strip of glass across the centre of the little bottle with the button rim.
 
I have never seen this in a glass bottle until just now when I cam across this very clearly shown similar bridging thread in an art glass bottle.
 
So just for interest I thought I would add it here whilst it was fresh in my mind.  The bottle may well not be Maltese, but the effect is very clearly shown and so here it is:

http://www.ebay.co.uk/itm/Art-Glass-Bottle-Vase-with-unusual-Joined-Thread-Inside-/351315515211

I hope it is still relevant to this long runnung saga as a good illustration of the inclusion in the bottle.

[flying free]

Hi Rosie

That belongs to a board member I think and might have been posted recently.   These 'bridges' appear fairly frequently around studio glass as a design feature, and are where a gadget has been poked through the sides I believe.  I think mine has as well to be honest.  I don' t think it was an accident.

m

[chopin-liszt]

I've got a strange strap in the middle of a Fish vase - it is not supposed to be there, it is decidedly an accident.

I was playing around with some very thick Tiger pattern inside-out bowls, putting them up to my kitchen cooker hood lights, and discovering there was a lot more to them than I have ever thought.

One of these, I am sure, has cobalt in it. Here are the pics I took - with and without being lit from inside.
(it's quite easy to tell which is which!)

[flying free]

I'm a bit undecided on that one Sue.  It doesn't have that slightly odd purple hue that Cobalt always seems to have when photographed.
To be honest photos can be difficult to tell, but that one looks like what I call in my head    Mdina 'navy blue'
and is similar to the left hand vase, bottom pic, that John posted here
http://www.glassmessages.com/index.php/topic,53678.msg304572.html#msg304572

Perhaps the bridge in my sidestripe is just a glitch in the making then.

m

[chopin-liszt]

It is always difficult with photos, there appears to be cobalt over teal in this vase. It's at a different depth. I thought I had managed to capture some clue of that in the second pic.

It all vanishes when lit from inside, because the light is extremely bright and it's over yellows and browns and teal anyway.
I'm having trouble with taking pics because the glasses I need to see the piece I'm photographing are different to the glasses I need to see the screen on the camera.

It's a completely different blue to John's one you showed - I have that piece. I was planning to photograph it next to my cobalt one to add here, just haven't done that yet.