The dataset contains experimental data for the publication Rac-Rumijowska, O., Markowski, P., Rauch, K., Suchorska-Woźniak, P., & Dziedzic, A. (2025). Development of Composite Thermocouple Materials Using PEDOT: PSS and Bi2Te3 for Wearable Thermopiles. Available at SSRN 5280281. Files a-g - microscopic images with metadata are presented in Figure 4 in the aforementioned publication. These are, respectively: Microstructure of the (a) clear surface of textiles; textiles covered by (b) silver paste, (c) PEDOT:PSS paste, (d,e) paste containing 70:30 PEDOT:PSS:Bi2Te3; (f) border of print from paste PEDOT:PSS and 70:30 PEDOT:PSS:Bi2Te3; (g,h) polyimide foil covered by paste 70:30; (i) SEM image of Bi2Te3 powder. Data in .xlsx format are measurement data for thermoelectric materials—resistance, Seebeck coefficient, and power factor. File descriptions are as follows: substrate (polyimide foil/kapton)_sample name.xlsx—sample names are the same as in the publication.