compound the chiral compound can be selected from non polymerisable chiral compounds for example conventional chiral dopants or polymerisable chiral compounds all of which can be mesogenic or non mesogenic suitable polymerisable chiral compounds are for example those of above formulae ik iq and iic iie further suitable chiral polymerisable compounds are for example the commercially available paliocolour u00ae materials from basf ag germany further suitable are chiral compounds with a high helical twisting power htp in particular chiral binaphthyl derivatives as described in wo 02 94805 chiral binaphthol acetal derivatives as described in wo 02 34739 chiral taddol derivatives as described in wo 02 06265 and chiral compounds having at least one fluorinated linkage group and a terminal or central chiral group as described in wo 02 06196 and wo 02 06195 all of which can be polymerisable or not suitable nonreactive chiral dopants can be selected for example from the commercially available r or s811 r or s1011 r or s 2011 or cb15 from merck kgaa darmstadt germany the references discussed in the previous paragraph also teach suitable non reactive chiral dopants the preferred amount of non polymerisable chiral compounds in the polymerisable lc mixture is from 0 1 to 10 preferably 0 5 to 6 the preferred amount of polymerisable chiral compounds is from 0 to 30 preferably 0 to 20 very preferably 0 to.