Data and experimental design which accompany the publication Curtin and Papworth (2020) Coloring and size influence preferences for imaginary animals, and can predict actual donations to species-specific conservation charities. Conservation Letters 13: e12723 (https://conbio.onlinelibrary.wiley.com/doi/full/10.1111/conl.12723). Two files of source data for "Patterning and size influence preferences for imaginary animals, and can predict actual donations to species specific conservation charities" (216 imaginary animals.csv and Survey 2_DCE results.csv). Also included is the experimental design (Survey 2_DCE design.xlsx) required to analyse Survey 2 in the R package 'support.CEs'. Properties of 'Survey 2_DCE results.csv' and 'Survey 2_DCE design.xlsx' are described in 'Properties of Survey 2_DCE design and results.txt'. Properties of '216 imaginary animals.csv' are described in 'Properties of 216 imaginary animals.txt'.