Purpose: This paper presents a comparative study, regarding cooling time and dimensional accuracy, of conventional injection mold cooling channel layouts, using straight holes and a baffle, and free-form fabricated (FFF) layout, manufactured by the direct-metal rapid tooling (RT) method electron beam melting (EBM). Many other methods have been proven useful for rapid tooling, but the authors have not found any publications where EBM has been used to manufacture injection molding tools. Design/methodology/approach: A test part was designed in order to replicate a common and important issue: inadequate cooling in deep cores. The part and the different cooling layouts were analyzed in an injection molding simulation software and the numerical results were compared with corresponding experimental results. Findings: The analyses showed an improvement in both cooling time and dimensional accuracy in favor of conformal FFF cooling channels manufactured by EBM. The experimental results correlate well with the numerical tests, however with some discrepancies. Research limitations/implications: The results presented are based on the direct-metal RT method EBM, and they were obtained using a specific test part. Orginality/value: This paper can be a useful aid when designing mold tools and especially when considering the usage of FFF cooling channels versus conventional cooling design. It can also serve as a reference when comparing the efficiency in terms of cooling time and dimensional accuracy between different layouts.