Modelling is something that requires models to dedicate themselves fulltime to maintaining and nurturing themselves in order to prove them the best in all aspects. As one needs to carry themselves just the perfect way in order to keep them up and going as a great model. Well there are certain attributes and traits that a professional model needs to follow in order to reflect a better image in the industry. These includes certain types of attitude as well as physical appearances. Mostly when it comes to commercial modelling and commercial models, certain professional attributes and traits are highly recommended and act as an essence for modelling career particularly if someone is looking for getting into commercial modelling.
Now, if we look at the tattoo side of modelling story, though it is a niche market in itself, but too small and short lived. Most of the times these tattoo models end up nowhere but just in some of the tattoo magazines. As a tattoo on a body limits them to what they represent and how they look, it makes a lot of difference when it comes to commercial photoshoots. So companies would reject models with tattoos if they are not found to be suitable enough for their ads.
Most models who have a tattoo on their body when get into some or other type of commercial modelling, they try to either remove or hide the tattoos with some cosmetics like Dermablend. Its common to be used by many top models like Angelina Jolie. The first option is too difficult especially for female models, so most of them prefer to go with the second option. However, its not good to have a tattoo if you are serious about a professional modelling career. This only adds some unhealthy traits to your profile and is in no way related to professionalism.