The effects of some pulp additives on mechanical, optical, and antifungal (Aspergillus terreus Ate456, A. niger Ani245, and Fusarium culmorum Fcu761) properties of papersheets produced from linen fiber pulp were evaluated. The ground materials (80 mesh) of Pinus rigida wood (PRW), Costus speciosus rhizomes (CSR), and Senegalia catechu rhizomes (SCR) were used as pulp additives at the concentrations of 0, 1, 2, and 4%. Papersheets with PRW at 2 and 4% as pulp additives had significant effects on tensile index with 26.41 and 30.22 N.m/g; burst index with 2.91 and 2.92 kPa.m2/g; and tear index with 2.52 and 2.53 mN.m2/g, respectively. The highest (64.36%) and lowest (62.90%) percent of brightness was observed in paper sheets produced from pulp without additives and CSR at 4%, respectively. Scanning electron microscopy showed that the produced papersheets with plant source additives had different degrees of decaying patterns, except for papersheets with PRW as additive, which showed some inhibition against the fungal growth. In conclusion, the mechanical properties of papersheets were significantly enhanced by the addition of the three pulp additives.