California Code, Elections Code - ELEC § 13207

(a) There shall be printed on the ballot in parallel columns all of the following:

(b) In the case of a ballot which is intended for use in a party primary and which carries partisan offices, voter-nominated offices, and nonpartisan offices, a vertical solid black line shall divide the columns containing partisan offices, on the left, from the columns containing nonpartisan offices and voter-nominated offices, on the right.

(c) The standard width of columns containing partisan offices, nonpartisan offices, and voter-nominated offices, shall be three inches except that an elections official may vary the width of these columns by up to one inch. The column containing presidential and vice presidential candidates may be as wide as four inches.

(d) A measure that is to be submitted to the voters shall be printed in one or more parallel columns to the right of the columns containing the names of candidates and shall be of sufficient width to contain the title and summary of the measure. To the right of or below the title and summary shall be printed, on separate lines, the words “Yes” and “No.”