black linework with not sharp.

this has happened with basically every order, some designs its not as big of a deal. and it has been fixed for me in the past. I believe they just clean the print head. I do like the quality of these stickers, the weight and finish are phenomenal. but the line work is very important to me. not sure how best to go about this. tell the people to clean the print heads more regularly? hope this is constructive