In this article, Dirac operators A η,τ coupled with combinations of electrostatic and Lorentz scalar δshell interactions of constant strength η and τ , respectively, supported on compact surfaces ⊂ R 3 are studied. In the rigorous definition of these operators, the δ-potentials are modeled by coupling conditions at . In the proof of the self-adjointness of A η,τ , a Krein-type resolvent formula and a Birman-Schwinger principle are obtained. With their help, a detailed study of the qualitative spectral properties of A η,τ is possible. In particular, the essential spectrum of A η,τ is determined, it is shown that at most finitely many discrete eigenvalues can appear, and several symmetry relations in the point spectrum are obtained. Moreover, the nonrelativistic limit of A η,τ is computed and it is discussed that for some special interaction strengths, A η,τ is decoupled to two operators acting in the domains with the common boundary .