Any tattoo can be affected by changes in size of the body, but the good news is that it's usually not that noticeable. Tattoos can be very forgiving, and if the weight gain or loss occurs slowly enough, this gives your tattoo time to "adjust". Imagine a balloon with a logo on it - I'm sure you've seen them. The logo appears essentially the same when the balloon is full as it is when it's deflated, with maybe a slight difference in depth of color. Your skin will usually not undergo as much size change as a balloon, so the changes in your tattoo should be even less visible. Your skin is very elastic and stretches and contracts without much incidence, in most cases. Stomach tattoos and pregnancy are possibly one of the exceptions, which will be discussed next.