A thermal recording material comprising: - a base layer; - one or more undercoat layers which is/are laid down on the base layer; - a thermo-sensitive coloring layer containing a leuco dye and a developer which is laid down on the uppermost undercoat layer, on the opposite side with respect to the base layer; and - one or more protective layers which is/are laid down on the thermo-sensitive coloring layer, on the opposite side with respect to the undercoat layer(s); wherein the one or more protective layers comprise(s): - polyvinyl alcohol; and - a bis[triazinyl-amino]-stilbene disulphonic fluorescent whitening agent, wherein the amount of dry mass of fluorescent whitening agent is 1.5 to 150 parts by mass relative to 100 parts by mass of dry polyvinyl alcohol, and wherein the fluorescent whitening agent has the following structure: wherein: n and m are each independently, 0, 1 or 2, but n and m cannot both be zero; M is H, ammonium or mono-, di-, tri- or tetra- C1-C4 alkyl- or C1-C4 hydroxyalkyl-ammonium, or M is a monocation metal equivalent or a half stoichiometric equivalent of an alkaline earth metal; R 1, R 2, R 3 and R 4 are C2-C4 hydroxyalkyl. - a base layer; - one or more undercoat layers which is/are laid down on the base layer; - a thermo-sensitive coloring layer containing a leuco dye and a developer which is laid down on the uppermost undercoat layer, on the opposite side with respect to the base layer; and - one or more protective layers which is/are laid down on the thermo-sensitive coloring layer, on the opposite side with respect to the undercoat layer(s); wherein the one or more protective layers comprise(s): - polyvinyl alcohol; and - a bis[triazinyl-amino]-stilbene disulphonic fluorescent whitening agent, wherein the amount of dry mass of fluorescent whitening agent is 1.5 to 150 parts by mass relative to 100 parts by mass of dry polyvinyl alcohol, and wherein the fluorescent whitening agent has the following structure: wherein: n and m are each independently, 0, 1 or 2, but n and m cannot both be zero; M is H, ammonium or mono-, di-, tri- or tetra- C1-C4 alkyl- or C1-C4 hydroxyalkyl-ammonium, or M is a monocation metal equivalent or a half stoichiometric equivalent of an alkaline earth metal; R 1, R 2, R 3 and R 4 are C2-C4 hydroxyalkyl. - polyvinyl alcohol; and - a bis[triazinyl-amino]-stilbene disulphonic fluorescent whitening agent, wherein the amount of dry mass of fluorescent whitening agent is 1.5 to 150 parts by mass relative to 100 parts by mass of dry polyvinyl alcohol, and wherein the fluorescent whitening agent has the following structure: wherein: n and m are each independently, 0, 1 or 2, but n and m cannot both be zero; M is H, ammonium or mono-, di-, tri- or tetra- C1-C4 alkyl- or C1-C4 hydroxyalkyl-ammonium, or M is a monocation metal equivalent or a half stoichiometric equivalent of an alkaline earth metal; R 1, R 2, R 3 and R 4 are C2-C4 hydroxyalkyl. n and m are each independently, 0, 1 or 2, but n and m cannot both be zero; M is H, ammonium or mono-, di-, tri- or tetra- C1-C4 alkyl- or C1-C4 hydroxyalkyl-ammonium, or M is a monocation metal equivalent or a half stoichiometric equivalent of an alkaline earth metal; R 1, R 2, R 3 and R 4 are C2-C4 hydroxyalkyl.