unikatissima's

Once I wanted to play a little bit with mosaic for a door board (see photo) but without having to buy all those materials. I didn’t know if I would use them ever more.
Therefore I figured out how to make my own mosaic stones from plaster and wrote a German tutorial.
I’m giving here a translation, see some photos at the German tutorial.

How to make your own mosaic stones:
You need:

• Plaster
• (Rectangular) plastic lid
• Water
• Brush
• Paint as used in school
• Vinegar
• Finish

What to do:

1. Make plaster following the instructions and cast a thin layer. The consistency should be yoghurt-like and the layer not thicker than 3mm / 0.07 inches.
   Note: Use the plastic lid of a margarine jar for casting.
2. After hardening paint the plaster cakes with the paints.
   Note: The cakes must have become hard, but they don’t have to be dry when painting.
3. After the cakes are dry (about one day) coat with the finish.
4. Then break the cakes into mosaic stones.
   Note: This can be done in an irregular way, but you can also score the cakes and then break in square or rectangular pieces.
   Note: The scoring of the cakes can best be done when the cakes aren’t dry. Although you can score dry cakes they break more easily than the moist ones.
5. Now make your mosaic by casting a form with plaster and setting your mosaic stones into the plaster.
   Note: To delay the hardening mix the plaster with some vinegar.
   Note: Only cast plaster in flexible forms because it expands slightly and you won’t be able to release it from a solid form.

Links:
Make your own mosaic stone (German)

Slow down drywall-plaster drying time with vinegar (English)
What to do to delay drying time of plaster? (German)
(Somebody here tried a drop of dish liquid in place of vinegar and said that it worked)