Synthetic Microfluidic Paper consists of slanted and interlocked polymer micropillars and can be used as a porous substrate in microfluidics and lateral flow assays. We here demonstrate single step manufacturing of multiple Synthetic Microfluidic Paper densities in the same device, and passive alignment of liquid spots in denser substrate regions, regardless of spotting position, allowing increased control of receptor positioning for lateral flow assays. We further demonstrate that the transparency of Synthetic Microfluidic Paper allows increasing readout signal intensity with increasing substrate thickness, to a value 3 times larger compared to nitrocellulose substrates.