  Slip transfer and blocking across grain boundaries was studied in a Ti foil
with a strong rolling texture deformed in tension. Prior to deformation, the
shape of the grains and the orientation of the grain boundaries were quantified
through laboratory scale diffraction contrast tomography (LabDCT). Mechanical
deformation led to the activation of <a> prismatic slip, and slip
transfer/blocking was assessed in > 300 grain boundaries by means of slip trace
analysis and electron backscatter diffraction. A categorical model was employed
to accurately assess slip transfer, and the "F1 score" of various slip transfer
criteria proposed in the literature was evaluated for the first time from 3D
grain boundary information. Remarkably, for the prismatic-dominated slip
transfer in the current Ti sample, the results show that the best predictions
of slip transfer/blocking are provided by the angle \k{appa}, which is directly
related to the residual Burgers vector, and by the Luster-Morris parameter m'.
In contrast, metrics based on the twist angle {\theta} and on the LRB criterion
were not able to predict accurately slip transfer/blocking. Thus, the extensive
analysis of the 3D grain boundary data and the novel application of LabDCT was
able to help clarify the role of grain boundary orientation on the mechanisms
of plastic deformation in polycrystals with strong prismatic-dominated slip.
