Single- and double-periodic 1D photonic lattices are formed in lithium niobate using both titanium in-diffusion and holographic grating recording. We investigate linear band structures and diffraction properties of such superlattices and observe a decrease of discrete diffraction with extra increasing modulation. In weakly-modulated superlattices with tailored diffraction properties, we demonstrate the formation of discrete solitons with propagation constant inside the mini-gap formed inside the Brillouin zone. © 2007 Optical Society of America.