At first, I recommend you to ONLY make a weight inside the smaller concrete mould when you make con- crete planters.. It helps concrete moulds to keep the same shape and can be used every time you make new concrete planters.
Prepare the mosaic by attaching double sided tape. Every chip needs to be fixed one by one. Paste the mosaic upside down on the tape. Do not remove the backpaper. Cut strictly along the external outline with a sharp knife (against a suitable surface). If the tape sticks out, it will make a print on the concrete plant- ers. Put the mosaic at least 5 mm apart, otherwise the concrete will not get into the slits. Take off the back paper and squeeze the mosaic into the concrete mould.
Fill the bigger mould with 6 kilos of concrete. Pad all around the concrete moulds to remove airbubbles. If you want to be sure – use your hand inside at the decoration spots. Put the weight inside the smaller mold. Press it down into the center – check if the points are even. Let the concrete dry in two days!
When you remove the concrete mould the tape usually sticks to the mould. If you have a lot of decorations, it can be hard to remove – use hot water (not burning hot) on the mold to expand the plastic and soften the tape. Gently scrape around the mosaic with a blunt knife. The concrete moulds can be used for concrete planters over and over again.