To avoid the needed of having to observe always spectrophotometric standard stars, we will construct a grid of standard fields that will be observed repeatedly to guarantee the stability of the sources and to improve their photometry. These fields will be calibrated against the SSSs and, therefore, the photometry of the stars in these fields will be tied to the same photometric system, becoming (those not variable) as standard stars for J-PLUS. Once the photometry and stability of many sources of these fields is considered enough reliable, the calibration of future observations will be done observing these fields instead of having to observed single SSSs.