Vegetable ivory obtained from the endosperm of jarina seeds (Phytelephas macrocarpa), native to the Amazon region, has been regarded as a sustainable alternative to elephant ivory; however, it is vulnerable to biodegradation due to its mannan polysaccharide composition. In this study, vegetable ivory was coated by atmospheric air plasma jet activation of silicone and copaiba oils. Stable, smooth, and crosslinked micrometric coatings were formed after 80 s of plasma activation. Water contact angle results show that hydrophobicity was enhanced without detrimental effects on the surface reflectance. The best antibacterial performance against Staphylococcus aureus and Escherichia coli was obtained for a 1:1 mixture of both oils due to the synergetic action of silicone hydrophobicity and copaiba bioactivity.