When printing with ABS, a common problem is warping. Warping is especially prevalent when printing big objects because by the time the extruder nozzle comes around to add a new layer on top, the bottom layer would’ve already cooled and thus the uneven heating causes the piece to warp like a bimetallic strip. The reason ABS requires a heated bed is to counter the warping effect so that the bottom layers are kept hot and thus around the same temp as the layer currently being extruded. The problem lays when you start building higher, then the middle layers are cooling because they are too far away from the heat bed.
This post will be refined later on. But the purpose of this post was to display the idea of using an acetone/ABS slurry. I claim no rights to this “idea” as I found it while looking on Instructables.com by the user TechShopJim. The idea is that you use acetone as a solvent and melt your scrap ABS pieces so that you create a slurry. By spreading this slurry on the build plate when it is cool, the acetone will evaporate when the bed heats up and thus leaving a thin film of acetone on the surface. Because the thin film is ABS itself, it adheres to the first layer of the print much easier than if the plastic were to be just extruded on the bare build plate glass. When the print is finished, it also makes it safer to remove the object because the thin film of ABS although supposedly maintains a larger surface area in contact with heated bed, comes off as one uniform bottom piece without running the risk of a partial strand ripping from the bottom of the print.