[Underglaze Fading after Firing]

On 7/10/2022 at 2:59 PM, Chilly said:

I have samples of all the glazes I own, and we have quite a few at the centre, but my comment referred to application bethod/ability, not colour.  But I do get them to do another test before glazing anything they think is "precious".

Ah, my mistake.

[Underglaze Fading after Firing]

Chilly, I have never considered that and will be wholeheartedly stealing the idea, thank you. I'm not sure about making tiles for every color all at once, but definitely for my next few colors I'll be trying that out. 

[Underglaze Fading after Firing]

I'm using commercial glazes, I don't have the space or money to make my own at the moment. I'm actually using the same clear amaco used in their guide (thank you for that), LG-10 Clear Transparent, which makes me wonder if its an issue with the glaze itself. I haven't had to dilute any of the glazes I used for the test tiles, so maybe it is that I just need more coats.

[Underglaze Fading after Firing]

I've been spending more and more time trying out new glazes, but I recently came into an issue while making test tiles. I've working with amaco brand velvet underglazes, and made up a pile of test tiles for the colors I currently have. I used the same procedure with all of them (bisque the tiles, two layers of underglaze, dry, two layers of clear, but on some of the tiles the color seems to have just vanished. I had the issue once before with a cup I had underglazed before bisque firing, but there the color faded during the second firing. I've attached a pictures of the fading tiles for reference.

Has anyone had these issue before? Am I screwing up the firing, or is it an issue with the glazes themselves? For reference, I'm firing in the 04-05 range.

Thanks in advance.