A method of manufacturing a security document, including: providing a polymer substrate having first and second surfaces; and: applying an array of focussing elements to the first surface of the polymer substrate across a first region; forming an image array by: providing a die form having a surface including an arrangement of raised areas and recessed areas defining the pattern; applying a first curable material to the surface of the die form so it substantially fills the recessed areas; bringing a pattern support layer in contact with the surface of the die form so it covers the recessed areas; separating the pattern support layer from the surface of the die form so the first curable material in the recessed areas is removed from the recessed areas and retained on the pattern support layer; and at least partly curing the first curable material in one or more curing steps.