It's not essential to use a trim piece, but it does finish it off nicely. There are brushed and polished metal trims you can use, but I think these normally need to be installed before the tiles are fixed. We have heard of some people having some trim pieces powder-coated in a matching colour - we may look into this ourselves in the future, but that's no help to you now. Another option is to use a timber moulding in a suitable profile (easily available from a hardware store) and take a sample of the tile in and have it colour-matched in paint.
Southern Cross Ceramics
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