10 ILCS 5/17-8
The county clerk shall provide in each polling place, so designated or provided a sufficient number of booths, which shall be provided with such supplies and conveniences, including shelves, pens, penholders, ink, blotters and pencils, as will enable the voter to prepare his ballot for voting, and in which voters may prepare their ballots screened from all observation as to the manner in which they do so. They shall be within plain view of election officers, and both they and the ballot boxes shall be within plain view of those within the proximity of the voting booths. Each of said booths shall have 3 sides enclosed, one side in front, to be closed with a curtain. Each side of each booth shall be 6 feet 4 inches and the curtain shall extend within 2 feet of the floor, which shall be closed while the voter is preparing his ballot. Each booth shall be at least 32 inches square and shall contain a shelf at least one foot wide, at a convenient height for writing. No person other than the election officers and the challengers allowed by law, and those admitted for the purpose of voting as herein provided, shall be permitted within the proximity of the voting booths, (i) except by authority of the election officers to keep order and enforce the law and (ii) except that one or more children under the age of 18 may accompany their parent or guardian into the voting booth as long as a request to do so is made to the election officers and, in the sole discretion of the election officers, the child or children are not likely to disrupt or interfere with the voting process or influence the casting of a vote. The number of such voting booths shall not be less than one to every 75 voters or fraction thereof who voted at the last preceding election in the precinct. The expense of providing booths and other things required in this Act shall be paid in the same manner as other election expenses.
Where electronic voting systems are used, a booth with a self-contained electronic voting device may be used. Each such booth shall have 3 sides enclosed and shall be equipped with a curtain for closing the front of the booth. The curtain must extend to within 2 feet of the floor. Each side shall be of such a height, in no event less than 5 feet, one inch, as to insure the secrecy of the voter. Each booth shall be at least 32 inches square, provided, however, that where a booth is no more than 23 inches wide and the sides of such booth extend from a point below the device to a height of 5 feet, one inch, at the front of the booth, and such booth insures that voters may prepare their ballots in secrecy, such booth may be used. If an election authority provides each polling place with stickers or emblems to be given to voters indicating that the person has voted, no person who has voted shall be denied such sticker or emblem.
10 ILCS 5/17-8