A tattoo can take anywhere from 10 days to two weeks to heal. A number of factors determine whether you will be a slow healer or fast healer; if a scab does or doesn’t form, if it is exposed to sunlight or tanning beds, if you scratch or abrade the tattoo in any way and your own personal body chemistry. In general, many people will over moisturize their tattoo, turning any scab into a pulpy mess. Scabs will retain dye and deposit the dye back into the skin over time. Ideally, you want a thin scab that falls off like a bad sunburn by trying to maintain a balance between too thin a layer of scab and too thick a layer of scab. Often, your tattoo artist will supply you with an ointment to apply twice a day for the first few days after the tattoo is finished. After this period has passed and there are no adverse complications, regular, unscented, uncolored moisturizer will do the trick applied in a thin layer twice daily. Make sure the moisturizer doesn’t have any sparkles.
You want to avoid covering up your tattoo too much so that it can heal, but you also want to avoid direct sunlight which can cause the ink to fade. Sharp Tattoos.com provides an excellent detailed set of instructions for post care of a tattoo.