Hi Matthew and thanks for such a detailed reply.
On consideration and reflection I was nursing a troublesome cold whilst being tattooed so it would appear my immune system was compromised leading to infection.
I am pretty careful with new tattoos but no-one is perfect so it’s probable germs got in and my already overworked immune system couldn’t hack it.
The ink was applied during a 3 hour session and was on virgin skin. The same guy has tattooed me for hours and hours before with no problems so I doubt it is technique etc.

A few more questions if possible:
how long to wait before having a fresh piece of skin on the SAME arm tattooed? Make sure all the infection has gone first to minimise the risk of cross infection?
what to moisturise with whilst the skin heals? I am currently using savlon to help fight the infection but also have some Dr Organic aloe vera based mosituriserif necessary. When to stop using savlon?
how long to moisturise? do I do it until all the scabs fall off?
Dressings – normally I don’t wear dressings. I just cover with loose clothing, wash once a day in the shower with anti bac soap, air dry for 1 hour then apply Bepanthan. What sort do you recommend? melanin dressings, plain bandage?

Thanks for your help, Chaz.