1.Normal – Default mode. The layer on top covers the layers below it.
2.Multiply – Multiply mode multiplies the pixel values of the upper layer with those of the layer below it.
3.Add – The pixel values of the upper and lower layers are added to each other.
4.Subtract – Subtract mode subtracts the pixel values of the upper layer from the pixel values of the lower layer.
5.Lighten – Lighten only mode compares each component of each pixel in the upper layer with the corresponding one in the lower layer and uses the larger value in the resulting image.
6.Darken – Darken only mode compares each component of each pixel in the upper layer with the corresponding one in the lower layer and uses the smaller value in the resulting image.
7.Average – This mode computes average value from pixel values of the upper and pixel values of the lower layer.
8.Difference – Difference mode subtracts the pixel value of the upper layer from that of the lower layer and then takes the absolute value of the result.
9.Negation – This one is the "opposite" of difference mode.
10.Screen – Screen mode inverts the values of each of the visible pixels in the two layers of the image. Then it multiplies them together.
11.Exclusion – Similar to difference mode but with lower contrast.
•Combination of some paint colors with some paint modes may result in no visible change (e.g. Add + Black or Multiply + White)