During the pandemic caused by SARS-CoV-2 (COVID-19), a paper analytical device (PAD) was proposed as a tool for remote laboratory classes for undergraduate chemistry to teach calibration curve concepts. For this experiment, students were taught how to prepare a PAD, calibrate standard solutions, construct a calibration curve, and treat data obtained by colorimetry digital image, by applying household utensils only. The proposed experiment was evaluated considering remote and in-person courses. More than 80% of the students in both groups reached grades greater than 60%. The students' survey demonstrated that 80 to 100% of the students (n = 6) agreed or strongly agreed that the experiment achieved the learning outcomes concerning the calibration curve. For 50% of the group, it was also found that colorimetric reactions could be more effective than the simple dye impregnation method.