I have Masters degree with Distinction and Student of the Year Prize in Corrosion of Engineering Materials from Imperial College London, first degree in Chemistry from University of Central Lancashire and also did Technology, Material Science and Engineering and Mathematics from the Open University.
In areas where tattooing is not as closely monitored, people are asked to wait for 12 months to give blood after getting a tattoo. This waiting period ensures that the donor is free of any potential blood-borne diseases which could have been passed on unsanitary equipment.
Piercings do not disqualify you from donating blood as long as they were done with single-use, disposable equipment. Tattoos also do not disqualify you from donating if they were done with a single-use needle at a licensed facility. If not professionally done, you must wait one year to donate blood.