I was using this at school. When I took some out to check, I noticed that some of them had separated into liquid and color. I don't know the weight of the unused portion, so please use this as a reference. Up to around 15g, there is about 90-70% remaining. Around 9g and 8g, there is about 30-20% remaining. This is based on my amateur estimation, so please only purchase if you understand this.