Speedball 001050 Underglaze, White by Speedball

Here’s a short, personalized review you can use: ⸻ I’ve been using the Speedball White Underglaze on my pottery pieces, and it’s been a great addition to my studio. Once I gave it a good stir and thinned it slightly, it brushed on beautifully—smooth and opaque in just two to three coats. I love using it for sgraffito and surface designs where I want crisp, clean lines, and it fires to a nice bright white under clear glaze. It holds up well through bisque and glaze firings, even at Cone 6. Definitely a solid staple for any potter looking to add reliable white detailing to their work. The only concern that I feel obligated to state about this product is that if you’re going to apply a clear glaze over it, you definitely should be using Speedball clear because it does not seem to like when I use another brand’s clear over it and will occasionally bubble or crack if I don’t use the Speed ball clear.. I called Speedball to ask them about this problem and they confirmed that this is a known issue.

Excelente producto, vino bien empaquetado y cumple con mis expectativas

We use this in our community pottery community studio. It helps if you water it down as it’s quite thick. But it looks great and we never have any issues with speedball underglazes.

I like that the bottle is the same width top to bottom, this allows even a wide brush to be dipped into the bottle easily. I use 3 coats at cone 6. The result is opaque, pure white without tints of other colors. Additionally, this white can be used in 2 or 3 coats beneath other glazes to give clean, bright results. White, red and brown clays can make glazes appear dull or "muddy", if you use this white in a couple of coats at greenware (recommended) or bisque, it's as if the glaze you apply over this underglaze has been applied to a porcelain type clay. You can use it alone or beneath other underglazes, other opaque or translucent glazes including clear. I've used this white to cone 10. If used alone to cone 10, be sure you have 3 full coats, allowing each coat to dry before applying another and if you're firing higher than cone 6, maybe add a 4th coat to be safe that you have good coverage. I've had this brown slightly in high fire, atmospheric firings such as wood fire, soda fire and salt fire. Hope helpful!

It works, but need many layers