Tanned leather artifacts are susceptible to microbiological
growth, causing deterioration when suitable temperature and
humidity conditions are found due to leather containing a
nutrient medium of protein and lipids. This study aims to
compare the antifungal activity between Zinc Oxide
(ZnONPs) and Titanium Dioxide (TiO 2  NPs) nanoparticles
against Aspergillus niger on the infected leather samples
through microbiological ageing. Also the author applied two
different techniques of applying nanomaterials via soaking
and spraying. Color changes; Mechanical properties (tensile
strength – elongation) and pH value have been measured to
estimate the stability of leather against Aspergillus niger. The
results revealed that ZnONPs can prevent the hyphal growth
of Aspergillus in comparison to untreated samples because of
the high antifungal activity in ZnONPs. Compared with the
control sample in which the inhibition growth percentage was
0%, the inhibition of growth ZnONPs against Aspergillus in
tanned leather, was treated by the soaking technique was 78%.
Also, the inhibition of the growth of TiO 2  NPs against
Aspergillus in the tanned leather sample treated by the same
soaking method was 22.2%. However, in the case of spraying,
the results were not satisfying as the inhibition of growth in
the case of ZnONPs was 32.4% but the inhibition of growth
in the case of TiO 2  NPs was 18.6%. The results proved a
decrease in the color change for both Zinc and Titanium
nanoparticles compared with the control samples. The author
found ZnONPs are better than TiO2 NPs in results of
lightness (L value), red-green color (a value) and yellow-blue
color (b value). The results showed a difference between the
ZnONPs and TiO 2  NPs results as ZnONPs is better than
TiO 2  NPs in Elongation and Tensile Strength. Also, the
soaking technique results are better than the spraying
technique. pH value proved the effectiveness of the ZnONPs
more than TiO 2  NPs in controlling Aspergillus due to the
enzymes produced by the fungi which affected and damaged
the leather samples. So, the author recommended the ZnONPs
in controlling the Aspergillus niger and preferred the soaking
technique rather than spraying for applying the materials.