
Trademark infringement occurs when you use another's trademark in a way that confuses consumers into believing the product you are selling originates with or is sponsored by the trademark owner. With the word "boycott" on the front, there won't be any question about your non-affiliation with the trademark owner.
Nearly all intellectual property issues are intensely fact-specific. Accordingly, you should consult with an attorney regarding the specifics of your intended use. This forum is not a substitute for personalized legal advice.