Moderate still life endeavors on various surfaces:

Two things I am struggling with:
1. Sunken-in: it is the appearance of a dull matte area in a section of an oil painting, usually caused by overly absorbent grounds, too much solvent, or earthy pigments. In my case, it is the umber and the black. I tried oiling out – apply one part Gamsol + one part Galkyd to the dull area. It helps for a while, but overtime, it might go back a little. Varnishing is supposed to be another way to improve, but so far I find that even less helpful. The process is demanding of patience too, for you need to wait till the paints touch dry to apply the rescue, and then wait for the rescue to dry to see if it actually works.
2. Taking a decent photo. I assume it would be better if the I wait long enough for the paints to be drier, and somehow there’s no sunken-in – the shine is even. Or, invest in a better than iPhone camera? 😳