Compatibility: Many treatments procedures require an introduction of diverse products or materials into the artifact. For this reason an Art Conservator must plan and study the possible interactions between different matters so that the intervent is stable in time. When integrating new products into an artwork an art conservator must acknowledge the variable properties that include response to changes in temperature and relative humidity, development of physical stresses from shrinkage, and the production of potentially harmful byproducts of deterioration. 

Reversibility: While integrating new materials into the artwork this should be as easy as possible removable in future interventions. Art conservators knowledge on conservation products leads them to choose a treatment in which these are compatible and soluble in solvents that will not interact with the constituting components of the artifact.

Some treatments such as cleaning old varnishes, require the utmost caution in the execution because some these are irreversible therefore the art conservator must undergo through a series of meetings with the client and board of directors before the project begins.

Differentiation:  This principle points out a distinction between the art conservator's incorporations and the original. There are multiple methods to approach this principle; Some suggest that this should be guided aesthetically while others consider that it is not necessary since its already diverse by its composition (linked to the solubility mentioned in the reversibility principle).

While inpainting, some schools make an aesthetic differentiation. This improves the comprehension and lecture of the artwork without impairing the image but when imitating the overall surface this could mislead the actual conservation state to the public. Employing recognizable inpainting like selezione cromatica, trateggio, astrazione cromatica minimise the distraction of losses and suggest the continuity of image to create the illusion of wholeness. Any kind of interventions should be limited only on the affected area.