stainer
nounUK /ˈsteɪnə/
US /ˈsteɪnər/
A stainer is a person or thing that puts color or marks on something.
The stainer carefully added red dye to the fabric.
OTHER MEANINGS
2. A substance or chemical used to add color to materials such as wood or fabric.
The carpenter applied a wood stainer before varnishing the table.
3. A device or tool used to apply stain or color.
She used a small stainer to paint the edges of the model.
4. A person who works in staining glass or textiles.
The stainer mixed pigments to create a rich blue glass.