## 1 Introduction
In reality, calibration for macro parts has a wide tolerance, as long as the part sticks to the surface and the nozzle remains unclogged printing is deemed acceptable. To enhance adhesion to the print surface and aid the removal of parts, the printer bed can be covered with painter's tape [25], though many studies elect to print directly on the bed. The challenges of consistent, and thin, single layers are especially apparent with the growing availability of self-assembled units and impact heavily on the financial requirements of implementing the printing of microscale layers. For example, [PERSON] et al. highlight that cross-sectional area changes with standoff distance in their empirical and CFD modelled study of single-layer extrusion. Further, they address a print surface misalignment that must be manually corrected [26]. These concerns are often not considered in the literature, where detailed optimisation and discussions are focused on bulk parts built up with many layers, rather than thin, flexible, structures comprised of a few or even single layers [27; 28; 29; 30; 31; 32; 33; 34]. A further unreported complication of printing thin structures, such as single layers, struts, and meshes is the difficulty in their removal from the printing surface, especially as good adhesion is required for successful printing. Thin layers are damaged when peeled from a printer bed, or adhesive tape, resulting in curling and warping, thus limiting the printing of thin architectures. Producing thin, single-layer samples for mechanical testing is therefore challenging. This limits the study of the effect of printing parameters on the physical properties of prints--it is difficult to distinguish whether it is the intra-layer polymer properties that have altered within a part or interlayer bonding. These effects would be better isolated and distinguished in separate single and multilayer studies. The use of soluble or breakaway material for support during 3D printing is a long-established technique to aid in the printing of complex shapes or overhanging sections of parts, introduced by Stratasys in 1999 [35]. This paper presents a new application of soluble support material to mitigate several existing issues in FFF 3D printing. Here, we extend the printing of supports through the introduction of an initial PVA (a water-soluble thermoplastic polymer) sacrificial layer to printed architectures. Harnessing this technique, we demonstrate the novel printing and removal of freestanding thin struts, at a thickness of approximately 25 \(\upmu\)m. The use of a sacrificial layer is shown to minimise the effects of both printer misalignment and poor calibration. Further, the effect of bed damage is reduced. Reduced printer-to-printer variation and looser calibration requirements provide an ideal solution for the deposition of consistent single or first layers. In this way, we hope to extend the utility of relatively inexpensive 3D printers into the production of microscale layers and meshes that may be useful in areas such as MEMS, microfluidics, tissue engineering, and photonics. Additionally, we hope this method might be used in the future to aid study into the effects of printing parameters on intra- and inter-layer properties in fused filament fabrication.