When you insert paper into the printer, the printer checks paper positioning and alignment. First, slide the front edge of the paper until it is justified against the stops. The right edge of the sheet must be positioned in the range indicated by a dashed line on the entry platen. (This range is +/- 7.5 mm from the nominal loading position.) After pressing the Load Media key, the printer advances the paper until the last margin passes over the paper sensor or enough paper has been fed through (depending on whether sheet or roll is selected). The printer is then able to work out the length of the sheet. The width is found by using the line sensor on the carriage.
To make paper loading easier, the printer will not reject any sheet that might be displaced and under the skew requirements. In this case the drawing will be offset on the y-axis.
Paper that is cut properly should not need the help of the skew tolerance feature. In fact, using this feature for properly cut paper increases the risk of skewing your print on the page.