Diffusion magnetic resonance imaging is a non-invasive tool to probe the microstructural features of a sample. One of these properties is the restriction size that can be measured by changing the diffusion time or alternatively changing the frequency content of the gradient waveform. B-tensor encoding was proposed recently to disentangle microstructural features of the tissue. Here we use the combination of linear, planar, and spherical tensor encoding to estimate the pore size in a biomimetic phantom, for which ground truth size estimates were available. The results show a good agreement between the estimated sizes and ground truth values.