A writing instrument includes a first reservoir for dispensing a first fluid having a first property of reflectivity. A first tip member is in fluid connection with the first reservoir. The first tip member has an end with a size and shape that corresponds to a response area of the response form. A second reservoir can be used for dispensing a second fluid, which is capable of modifying the first property of reflectivity when covering the first fluid. A second tip member is in fluid connection with the second reservoir. The second tip member has an end with a size and shape that corresponds to the response area of the response form.