3D printed Acrylonitrile Butadiene Styrene (ABS) and Polyvinyl Alcohol (PVA) polymer structures were coated and infiltrated with alumina (Al2O3) using the trimethylaluminum(III) (TMA) and water ALD process. Coating studies on ABS were carried out at 80˚C, which resulted in a 203 nm thin film with a 1.35 Å growth per cycle (GPC). The thin film was a well-adhered protective overcoating which prevented the reaction with acetone vapors in solvent resistance experiments. Infiltration studies on ABS and PVA structures were preformed at 130˚C and 80˚C respectively, to alter their physical properties. Differential Scanning Calorimetry (DSC) was used to determine the Glass Transition Temperature (Tg) of the polymers pre- and post-deposition after varying the number of ALD cycles, resulting in a change of ~ 9˚C and ~ 27˚C for ABS and PVA, respectively. After one heat cycle the post-deposition Tg reverted back to its pre-disposition point indicating reversibility of the deposition effects.