Several things affect the length of time it takes for a tattoo to heal. The itching is part of the healing process but normally happens when the tattoo is dry and scabbing over. It can be as short as 4 days, and for a very big tattoo could be more like 10 days.
There are three things that you must not do :
Pick the scabs - this could take the ink out of the skin and you will have to go and have the tattoo touched up
Do not use cotton Wool - this has too many small fibres and there is a chance that they will all get into your tattoo and make the itching worse and the ink colour uneven.
Do not use Vasoline - Many people recommend using petroleum jelly and covering with cling-film, however, these are good for keeping the tattoo clean until you get home and can wash it. A warm, damp, open wound is a great breeding ground for bacteria, so I would really recommend against this method.
The main aim is to keep your tattoo as clean as possible. The skin does a good job of this in the first day or two, as it will naturally weep. There are several different methods people use, all of which can be purchased over the counter. Most people I know who have lots of tattoos use Bepanthon - which is a nappy rash cream, but this makes it perfect to combat both the itching and promote healing whilst preventing the skin from drying out.
Once you come back from the tattoo parlour:
- Wash the tattoo with a mild soap and pat dry very gently - don't rub it!
- Apply Bepanthon all over
- Do not scratch it, as you will make it feel more itchy and germs from under your nails could infect it
- Wash and reapply cream every 3-4 hours
If your tattoo is somewhere where clothes rub, or if you feel discomfort during the night, then you could cover with cling-film then, but be sure to get the air to it during the day.