Heat-resistant wrapper paper for aerosol-generating articles

Aerosol-generating article which comprises a wrapper paper and an aerosol-generating material, wherein the aerosol-generating article is configured to be heated, but not burnt, wherein the wrapper paper wraps the aerosol-generating material, wherein the wrapper paper comprises pulp fibers and a char-former, wherein the pulp fibers make up at least 70% and at most 95% of the mass of the wrapper paper, wherein the char-former is at least substantially uniformly distributed over at least 70% of the surface area of the wrapper paper and the char-former is contained in a concentration of at least 5% and at most 20% with respect to the mass of the wrapper paper and is present in a concentration in the wrapper paper such that the quotient r=RT/Ro of the tensile strength Ro, measured in accordance with ISO 1924-2:2008 under the conditions of ISO 187:1990, and of the tensile strength RT, measured in accordance with ISO 1924-2:2008 under the conditions of ISO 187:1990 after the wrapper paper has been exposed to a temperature of 230° C. for one minute, is at least 0.20 and at most 0.90, and

• wherein the proportion of said char-former is higher on one side of the wrapper paper than on the other side and the side with the higher proportion of char-former faces the aerosol-generating material.