Methods and kits for treating a fibrous substrate prior to forming an image thereon are provided. The method can include positioning a treatment sheet adjacent to the fibrous substrate, transferring a salt (e.g., calcium chloride, magnesium chloride, or a mixture thereof) from the treatment sheet to the fibrous substrate using a wetting solution (e.g., an aqueous solution, such as water) to carry the salt from the treatment sheet into the fibrous substrate, and drying the fibrous substrate such that the salt remains in the substrate. For example, the transfer of the salt from the treatment sheet into the fibrous substrate can be accomplished via pressing the backside of the treatment sheet such that the wetting solution flows from the treatment sheet into the fibrous substrate while carrying the salt.