This article is focused on the utilization of tangent curve for description of mechanical behaviour of pressed mixture under compression loading. The aim of this experiment was to determine the general equation describing deformation characteristics of pressed mixtures under compression loading and to verify this equation. The experiment was carried out using mixture of seeds of common sunflower (Heliantus annuus L.), jatropha (Jatropha curcas L.), garden pea (Pisum sativum L.), common bean (Phaseolus vulgaris L.), and also mixture of spruce wood chips and waste paper chips. The results from the experiment showed that mechanical behaviour of the pressed mixtures under compression loading can be described by tangent curve function. From the determined coefficients of determination R2 it was clear that fitted tangent curve functions described the measured amounts exactly for all pressed mixtures. It can be therefore assumed that this tangent curve function is appropriate for use in pressing any pressed mixtures during linear compression.