There are 2 important things to remember when painting translucent objects that have textured surfaces such as clementines, oranges or lemons:
Form takes precedence over pattern; and don’t confuse bright with light.
When rendering a spherical or rounded object such as a piece of fruit, you need to make it appear 3 dimensional by focusing on the values that create its form, rather than any patterns that create texture on the surface. With a clementine, you simply ignore the dimpling in the skin and paint the shadow areas first, followed by the middle value sections and on into the lights. Block this in during the under painting stage and ignore the surface texture completely. When you are ready to go to color, you begin the same way, working from your shadow areas through the mid tones all the way through the lightest areas. This is where the light versus bright concept comes into play.
To make the shadow colors on the fruit above, first I mixed ultramarine and alizarin to create a violet-blue. I then mixed cadmium red light and cadmium yellow medium to make an orange the correct color of the medium value of the celmentine’s skin color. I mixed these two together (the violet-blue and the middle value orange) to create the shadow color, which I then blocked in. Next I took the middle value orange by itself and laid it in on the areas that were in the middle value range on the fruit, with a slight overlap where they met the shadows already blocked in. To create the lightest areas of the fruit, I simply added more cadmium yellow to the middle value orange. I did not add any white to the orange color of the skin, doing so would have made it lighter and duller, rather than brighter and more vibrant. White dulls colors down and can make them appear chalky, always ask yourself is it lighter or is it brighter, if it’s brighter, avoid the white!
To add a suggestion of the surface texture on the skin, I implied a few of the dimples with a few small brush strokes of middle value color into the shadow areas and few strokes of shadow color in the mid tones. You don’t need to paint every little dimple on the skin! Doing so would just cause confusion and probably diminish the 3 dimensional form you just worked so hard to create! Also, when applying the highlights, remember to add a little bit of yellow to the warm ones and some blue to the cool ones, rather than just white by itself, temperature is important. If you apply the highlights with a brush that is a little bit “beat up” you can actually imply even more of the skin texture, but don’t overdo it.
For the peeled segments of the fruit, you take the same approach as for the skin. Block in the forms first, work through the shadow areas and ignore the surface texture of the white membrane. When you are ready to paint the membrane (I’m told it is called “pith”), remember to only add the most prominent strands of it, just as with the skin, you don’t want to to overdo the surface texture. Keep the parts of the pith in the shadow areas cool in tone by adding some blue violets in the white, and the parts in light warm with some yellows added into the white.
Translucent objects are a challenge to paint, others you might enjoy trying include lemons, limes, or onions (especially the skins). If you remember to focus on form and value and brights vs. lights, your fruit will look naturally translucent and appealing, good enough to eat!