A "glossy mailer" refers to a promotional or advertising material that is printed on shiny, high-quality paper. It is typically used to attract attention and make a good impression on the recipient. Full definition
When he got home he found a glossy mailer with his face on it, rendered in somewhat sinister black and white. (wrvo.org)
«It's offensive that Bill Larkin is using taxpayer money to send out a glossy mailer claiming that he is «protecting taxpayers.» (nystateofpolitics.com)
«Under this system, state taxpayers would be forced to shell out hundreds of millions of dollars for negative television commercials, glossy mailers and the robocalls people hate,» said Senate GOP Leader Dean Skelos in a statement released this afternoon. (nystateofpolitics.com)