A method for depositing droplets onto a substrate utilising an apparatus comprising: an array of fluid chambers separated by interspersed walls, each fluid chamber communicating with an aperture for the release of droplets of fluid and each of said walls separating two neighbouring chambers; wherein each of said walls is actuable such that, in response to a first voltage, it will deform so as to decrease the volume of one chamber and increase the volume of the other chamber, and in response to a second voltage, it will deform so as to cause the opposite effect on the volumes of said neighbouring chambers; the method comprising the steps of: receiving input data; assigning, based on said input data, any of the chambers within said array as either firing chambers or non-firing chambers so as to produce groups of one or more contiguous firing chambers separated by groups of one or more contiguous non-firing chambers, wherein, within said array, there are differing numbers of contiguous firing chambers, or differing numbers of contiguous non-firing chambers; actuating the walls of certain of said chambers such that: for each non-firing chamber, either the walls move with the same sense or they remain stationary; and for each firing chamber, either the walls move with opposing senses, or one wall is stationary while the other is moved; said actuations resulting in each said firing chamber releasing at least one droplet, the resulting droplets forming dots disposed on a line on said substrate, said dots being separated on said line by gaps corresponding to said non-firing chambers. an array of fluid chambers separated by interspersed walls, each fluid chamber communicating with an aperture for the release of droplets of fluid and each of said walls separating two neighbouring chambers; wherein each of said walls is actuable such that, in response to a first voltage, it will deform so as to decrease the volume of one chamber and increase the volume of the other chamber, and in response to a second voltage, it will deform so as to cause the opposite effect on the volumes of said neighbouring chambers; the method comprising the steps of: receiving input data; assigning, based on said input data, any of the chambers within said array as either firing chambers or non-firing chambers so as to produce groups of one or more contiguous firing chambers separated by groups of one or more contiguous non-firing chambers, wherein, within said array, there are differing numbers of contiguous firing chambers, or differing numbers of contiguous non-firing chambers; actuating the walls of certain of said chambers such that: for each non-firing chamber, either the walls move with the same sense or they remain stationary; and for each firing chamber, either the walls move with opposing senses, or one wall is stationary while the other is moved; said actuations resulting in each said firing chamber releasing at least one droplet, the resulting droplets forming dots disposed on a line on said substrate, said dots being separated on said line by gaps corresponding to said non-firing chambers. receiving input data; assigning, based on said input data, any of the chambers within said array as either firing chambers or non-firing chambers so as to produce groups of one or more contiguous firing chambers separated by groups of one or more contiguous non-firing chambers, wherein, within said array, there are differing numbers of contiguous firing chambers, or differing numbers of contiguous non-firing chambers; actuating the walls of certain of said chambers such that: for each non-firing chamber, either the walls move with the same sense or they remain stationary; and for each firing chamber, either the walls move with opposing senses, or one wall is stationary while the other is moved; said actuations resulting in each said firing chamber releasing at least one droplet, the resulting droplets forming dots disposed on a line on said substrate, said dots being separated on said line by gaps corresponding to said non-firing chambers. for each non-firing chamber, either the walls move with the same sense or they remain stationary; and for each firing chamber, either the walls move with opposing senses, or one wall is stationary while the other is moved; said actuations resulting in each said firing chamber releasing at least one droplet, the resulting droplets forming dots disposed on a line on said substrate, said dots being separated on said line by gaps corresponding to said non-firing chambers.