What techniques did Leonardo use to give more realism to the painting of the last supper?

How much booze do taxpayers buy Nancy Pelosi? The meeting of representative for the purpose of writing laws and advising the king became? What type of music did Napoleon Bonaparte like? Are ceramic bearings better than steel? What kind of art does the artist known as seen produce? What do they do with the locusts in Things Fall Apart by Chinua Achebe? Where did Leonardo da Vinci live in his lifetime? Where to find Nurse Jackie's Scarf? Who is a famous author whose last name starts with T? When was The Starry Night painted? What is wrong with 1994 VW Golf when you turn on the ignition key and you just hear a ticking sound and sometimes if you try it again it will start to turn engine? How do you remove spray paint from card board boxes without damaging the design on it? Which is better for a digital camera with 12 mega pixels a li-ion or ni-mh battery? What is a paper collage? How many electrons are there in Mg2? How Long Did the BAM Earthquake Last? Where can you buy Mario Party 5? What is a synonym for go that starts with the letter C? How do you find the timing marks for the timing chain of a 2004 Nissan Armada? How many troops were available to Napoleon when he returned to Paris in 1815?

What techniques did Leonardo use to give more realism to the painting of the last supper?