Underglaze Colors Explained | Big Ceramic Store

UNDERGLAZE MARKER COLORS - EXPLAINED

Occasionally customers will look at an underglaze marker and think they've received the wrong color. This happens because the pre-fired color of the marker looks different than a post-fired color (which is represented on the packaging).

Generally speaking, two chemical lend themselves to this type of product: Cobalt and Red Iron Oxide. They are used in combination to get the marker colors.

Post-fired, the chemicals combine as follows:

Blue

= Cobalt

Slate

= Cobalt + Red Iron Oxide

Terra Cotta

= Red Iron Oxide

However, pre-fired, the color of the Slate marker is deceiving. The Red Iron Oxide dominates and the marker looks like it might be a Terra Cotta marker. This is because before firing, the Cobalt is not very vivid and only slightly darkens the Terra Cotta color of the Red Iron Oxide.

So, if you ordered slate marker and the label says "slate", but it looks Terra Cotta, everything is fine. It's just the pre-fired color.

UNDERGLAZE CHALK-CRAYON COLORS - EXPLAINED

Occasionally customers will look at an underglaze chalk-crayon and think they have gotten the wrong color. This happens because the pre-fired color of the chalk-crayon looks different than in a post-fired color. A couple of the colors look very similar pre-fired, and also look unlike the post-fired color Here's the most common example.

Dark Blue vs. Lilac

Lilac:

Pre-fired - Slightly darker and more purple looking

Dark Blue:

Pre-fired - Slightly more pink or pastel looking

Note:

It is often the easiest to tell the difference by looking at the end of the chalk, not the sides.

So, if you ordered a Dark Blue chalk-crayon and it came wrapped in paper that says "Dark Blue", but it looks like Lilac (or pink), everything is fine. It's just the pre-fired color.