Why your cosmetic tattoo fades???

few reasons which make sense ....

 Dead skin - its a natural process, when new skin cells are generated the dead cells are thrown out and they were erased minimally by your daily face washes and maximum wash by chemical peels and abrasions, 

pigments placed just an inch below your skin, as skin losses the inches, your pigments were also thrown out

pigments- organic pigments fades faster than inorganic because of their solubility 

Skin treatments - like chemical peels, medicated cleansers, lasers, skin polishing, parlour activities acne creams, skin lightening creams, scrubbers, etc which were used to lighten your skin will also lighten your pigments 

Nanno pigments - when the pigment powders are very minute they were digested easily by your immune system and they dissolve faster

Diluents,- if the pigment powders are mixed very thick or watery, either way they they will not stray longer, thicker pigments could not reach beneath and watery pigments flows with the blood flow.

and if pigments are placed very deep into the skin, then also there will be no retention

Topical anaesthetics- alkalises the skin - dispersal of the pigment within the skin 

other medications- like using blood thinners, antibiotics for long time, 

sunlight- can change the iron oxide colors to look more darker and also fades away the tattoo