Abstract: There is provided at least one molding segment in a modular molding kit or system. The molding segment comprises a rearward attachment and an alignment surface that define an angle there between. Placing the rearward attachment side against a wall and placing the alignment surface proximate to a ceiling thereby forms an alignment gap between the alignment surface and the ceiling. The molding segment optionally includes an alignment wedge, and possibly a compressible lip, to cover the alignment gap to adapt to non-planar surfaces and thereby produce the appearance of a unitary molding piece that is mounted flush to both the wall and the adjacent ceiling. One embodiment further includes an integrated covering segment extending from and conjoined to a side edge of a forward decorative surface. The integrated covering segment is adapted to cover a seam formed between the forward decorative surface and a second molding piece mounted adjacent to the forward decorative surface.