When your design goes through the glazing process, the part of your model which sits on the surface will not be glazed. Often it’s tricky for our fabricators to guess which way up your model should be - we can make an educated guess (things like mugs and plates are usually pretty obvious!) but this isn’t always the case.
To avoid any confusion or disappointment, the best thing to do is make it super clear which part of your model should be the base . We recommend recessing the words “UNGLAZED BASE” or even just “BASE” on this bottom part of your design which you would like to remain unglazed:
The words don’t have to be big, or recessed very deeply - they just need be just visible enough so that we can see which way up your model should be.
If you look at the bottom of coffee mugs, plates and bowls you see that they do not have a flat base. In order to get a better result from glazing, and minimize to the amount of area that is unglazed, designers will create a concave area in the base. You can see that in this rendering. A ring has been added that slightly elevates the vase creating a smaller contact area for the vase to rest on while the glaze is fired.
The section of this ring is detailed here with indicative dimensions:
And here is an image showing what the unglazed base of your model will look like: