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.
The whole process usually takes about an hour to donate whole blood, and a little over an hour for double red cell donation. When donating platelets, the whole process takes approximately two hours. The blood donation itself usually takes 5-10 minutes for whole blood, 25 minutes for double red cell donation and up to 2 hours for platelet donation.