Wash. Rev. Code § 29A.32.060
Committees shall write and submit arguments advocating the approval or rejection of each statewide ballot issue and rebuttals of those arguments. The secretary of state, the presiding officer of the senate, and the presiding officer of the house of representatives shall appoint the initial two members of each committee. In making these committee appointments the secretary of state and presiding officers of the senate and house of representatives shall consider legislators, sponsors of initiatives and referendums, and other interested groups known to advocate or oppose the ballot measure. Committees must have the explanatory and fiscal impact statements available before preparing their arguments.
The initial two members may select up to four additional members, and the committee shall elect a chairperson. The remaining committee member or members may fill vacancies through appointment.
After the committee submits its initial argument statements to the secretary of state, the secretary of state shall transmit the statements to the opposite committee. The opposite committee may then prepare rebuttal arguments. Rebuttals may not interject new points.
The voters' pamphlet may contain only text argument statements prepared according to this section. Graphs, charts, photographs, cartoons, or caricatures are not permitted.
RCW 29A.32.060