Methods and devices for producing a polymer at a location of a substrate are provided. In the subject methods, a fluid droplet containing a first monomer labeled with a first detectable label is deposited from a fluid deposition device onto a location of a substrate surface having a second monomer labeled with a second detectable label. The first and second detectable labels are then detected to determine any misalignment between the fluid deposition device and the location of the substrate surface during deposition. Also provided are algorithms that perform the subject methods, as well as fluid deposition devices that include the subject algorithms. The subject invention also includes arrays produced according to the subject methods and kits that include the subject arrays.