Abstract: In the process for rendering textile materials, especially cellulose-containing tent fabrics, fire-resistant by condensing dicyandiamide with formaldehyde and phosphoric acid, followed by dilution with water and application to the fabric, it has been found that the need to dilute the condensate and apply it promptly after formation can be avoided provided additional phosphoric acid is added from about 0 to 8 hours prior to the dilution. Without such additional phosphoric acid, if the dilution is later effected an insoluble precipitate will form. Thus, the invention permits production and shipping of a clear solution which, to be used, need only be diluted first with additional phosphoric acid and then with water. The initial condensation is preferably effected with about 0.9-3 moles of formaldehyde per mole of dicyandiamide in aqueous solution at a pH of about 8 to 13 and thereafter about 0.06-0.6 mole of phosphoric acid per mole of dicyandiamide and at least about 0.