Applications of customized biofilm reactors have markedly enhanced the productivity of different bioproducts. Implementation of novel concepts in designing of cost effective, durable and commercially scalable substrata has proven their positive impacts on the product features. To make such approaches more generalized in biofilm reactor technology, it is important to highlight the factors that decisively act on the compatibility between microorganisms and solid supports used for different bioproducts. The contents of the review have been strongly oriented towards the broader application of substrata for many bioproducts. Correlations between the variations in the product features and biofilm associated factors have been highlighted. Plastic composite support has been given a special attention. Some of the thermodynamic and interface properties of microorganisms and substrata have been considered. Role of extended Derjaguin, Landau, Verwey, Overbeek theory in assigning the parameters for substrate selection has been discussed. The influence of water structure on the formation of biofilm, and quantitative analysis of physical factors namely adhesion energy, contact angles and primary/secondary minima in selection of substrata have been well addressed. The key issues taken into the consideration and suggestions made in context of the present review can further aid in the customization of biofilm reactor technology.