Traditionally tensile test specimens have been designed so that the uniformity of the strain field across the gauge section is maximized. The displacements in the gauge section are then averaged to obtain a stress strain curve of the material from which different parameters such as yield strength (YS), ultimate tensile strength (UTS) and elongation to fracture can be determined. The development of full field measurement techniques like digital image correlation (DIC) enables the use of new types of tensile tests with more complex specimen geometries, as strain uniformity across large gauge sections is no longer needed. A novel method on using tapered specimen geometry to introduce variable strain levels in strain-hardening tensile specimens is introduced. A continuously widening tensile specimen cross-section is used to induce a continuous strain gradient along a gauge section, so that the strain level varies from pre-determined maximum strain all the way to zero strain. This type of tensile testing can be used with full-field measurement techniques to study phenomena like static strain aging in which the strain prior to heat treatment is critical in determining how the thermomechanical processing determines the subsequent material behaviour. Typically, a large test matrix with different samples for each combination of pre-straining and heat treatment is needed to characterize the strain aging behaviour of material. Preliminary results on nodular cast iron show that the method is promising, and with reasonable assumptions about the strain rate sensitivity the results can be directly compared with those of a conventional test matrix. However, with nodular cast iron some heterogeneity and discontinuous behaviour in the strain field is observed due to microstructural features such as graphite nodules and casting defects, which complicates the analysis. In this work, the method is validated with tests on steel specimens with more homogenous microstructure, resulting in more reproducible deformation behaviour and reduced uncertainty in the strain measurement. The trade-off between strain resolution in the final tensile test and strain resolution of the applied pre-strain, mediated by the virtual strain gauge size of the DIC measurement and the shape of the tapered specimen, is quantified.