A method of forming a porous tool, the porous tool defining an x-direction, a y-direction, and a z-direction, the porous tool comprising a mold body, a non-porous support structure on the mold body, and a porous structure on the non-porous support structure, the method comprising: depositing a first layer of additive material on a build surface using a directed energy deposition system to form a support layer, the first layer of additive material defining the non-porous support structure; depositing a second layer of additive material on the first layer of additive material using the directed energy deposition system while simultaneously subtracting selected portions of the second layer using laser ablation to form interconnected passages that traverse through the second layer in the x-direction and/or the y-direction; depositing a third layer of additive material on the second layer using the directed energy deposition system while simultaneously subtracting selected portions of the third layer of additive material using laser ablation to form an array of pores that traverse through the third layer of additive material in the z-direction, the array of pores in fluid communication with the interconnected passages, wherein the second layer of additive material and the third layer of additive material define the porous structure; finishing a lateral edge of the porous structure to provide a finished lateral edge comprising an array of edge pore openings, the array of edge pore openings in fluid communication with the interconnected passages; finishing a surface of the porous structure to provide a finished surface comprising an array of surface pore openings, the array of surface pore openings in fluid communication with the array of pores in the third layer of additive material; wherein one or more of the edge pore openings of the array of edge pore openings are aligned with one or more outgas vents positioned in the mold body; and (a) separating the non-porous support structure from the build surface and attaching the non-porous support structure to the mold body; or (b) depositing additional additive material onto the porous structure to form the mold body, using the directed energy deposition system. depositing a first layer of additive material on a build surface using a directed energy deposition system to form a support layer, the first layer of additive material defining the non-porous support structure; depositing a second layer of additive material on the first layer of additive material using the directed energy deposition system while simultaneously subtracting selected portions of the second layer using laser ablation to form interconnected passages that traverse through the second layer in the x-direction and/or the y-direction; depositing a third layer of additive material on the second layer using the directed energy deposition system while simultaneously subtracting selected portions of the third layer of additive material using laser ablation to form an array of pores that traverse through the third layer of additive material in the z-direction, the array of pores in fluid communication with the interconnected passages, wherein the second layer of additive material and the third layer of additive material define the porous structure; finishing a lateral edge of the porous structure to provide a finished lateral edge comprising an array of edge pore openings, the array of edge pore openings in fluid communication with the interconnected passages; finishing a surface of the porous structure to provide a finished surface comprising an array of surface pore openings, the array of surface pore openings in fluid communication with the array of pores in the third layer of additive material; wherein one or more of the edge pore openings of the array of edge pore openings are aligned with one or more outgas vents positioned in the mold body; and (a) separating the non-porous support structure from the build surface and attaching the non-porous support structure to the mold body; or (b) depositing additional additive material onto the porous structure to form the mold body, using the directed energy deposition system. (a) separating the non-porous support structure from the build surface and attaching the non-porous support structure to the mold body; or (b) depositing additional additive material onto the porous structure to form the mold body, using the directed energy deposition system.