Washington’s state Elections Division is sending out postcards to 140,000 state residents who appear eligible to vote, but haven’t yet registered.

Many of the cards will go to new 18 year olds and to millennials between 19 and 35. The mailings will have a catchy, humorous graphic and information on how to quickly register online by Oct. 10. About 21,000 will go to 18 year olds and 72,000 to those 19-35.

Eligible but unregistered 18 year olds will receive this postcard:

Half of eligible but unregistered 19-35 year olds will receive this postcard:

Half of 19-35 year olds and all 36 and over will receive this postcard:

The Elections Division is working with researchers from Pew Charitable Trusts and will analyze the response to see which design has the higher registration rate to help improve future outreach materials.

Each postcard notes that the recipients aren’t on the voter rolls and that they are invited to register online or by mail by Oct. 10 in order to take part in the General Election. First-time Washington voters may also register in person at their county elections office by Oct. 31.

Washington residents are eligible if they are at least 18, a U.S. citizen and not under custody of the Department of Corrections.

“We hope these postcards will provide just the boost people need to go online and get registered,” said Secretary of State Kim Wyman, the state’s chief elections officer. “It’s simple and secure and we really want them to begin a lifetime of voting and involvement in their community.”

Wyman plans a college civics tour this next week, and regularly visits colleges, high schools and groups where she promotes voting, volunteerism and civility.

The mailing list was generated by information from the Electronic Registration Information Center (ERIC), a nonprofit organization of member states that helps improve the accuracy of voter lists and provides information on unregistered potential voters that states can contact.

The postcard mailings are now in their fifth year and have reached 1.7 million potential voters.