Hi Gina Thinking more about the colours you have (which I will be ordering shortly). Do you premix quite a bit in the oil and refrigerate for later use (just thinking about my dislike for the messiness of mixing each time). I don't think a preservative would be required for the oil/colour suspension? Ross Spencer 24 Ocean View Place Rakaia Huts RD3 Leeston Check out my soap and <http://wild-hybrid.co.nz/> jewellery