Sub-millimetre resolution is desirable for laminar-fMRI to reduce partial-voluming with neighbouring tissues. CSF signal fluctuations can be a confound in voxels that lie at the CSF-GM interface due to physiological processes such as activation. The 3D-EPI readout, used with sub-millimetre fMRI studies, suppresses the CSF signals (long-T1 vs. short-TR). However, the degree of suppression is dependent on the flip angle used. In this study, we investigate the signal contributions of different tissue compartments by systematically varying the flip angle and map the flip angle dependence of tSNR as a function of cortical depth at 0.8 mm isotropic resolution at 7T.