Earth Brush
This magic item comes to us from the earthenware works of Pertasofolos Lan: a writing-brush as long as a grown man is tall. It can be used like any other brush, for oversize calligraphy, but its true power is in “painting the earth.” If dipped into an earthenware pot containing a given kind of stone or soil and then applied to a surface, it will cover that surface in a layer of the same kind of stone or soil. The source material in the pot is never depleted, but the brush must still be dipped repeatedly, as if the pot were filled with ink and normal (oversize) calligraphy were taking place. The resulting layer of earth is about a finger’s thickness, but it may be painted over with more layers. Perhaps the most magical aspect of this brush is that – no matter what it is dipped in – it is able to take up a new medium without the need for washing in between.
Originally eight such brushes were known to exist, but several have been lost or destroyed. At least one is owned by the High Court of the Tal, where it is used in the maintenance of the Court’s extensive garden complex.

Like this one… minus the smarmy idiot.
(The name for this week’s magic item comes from The Forge.)
(Image source here.)