What is the best way to make a substantial amount of soot in a high school laboratory? I need to make about 50 grams of soot (carbon black particles) in a high school laboratory. What would be the best way to do this?

The purpose of needing 50 grams of soot is because I would like to carry out an experiment that investigates how the percentage soot in oil (e.g. diesel) affects the viscosity of the mixture. To measure the viscosity, I would have to put 500 ml of oil in a measuring cylinder and do the ball-bearing method. The highest percentage I would like to test is 10% soot and that calls for around 50 g of it.
There is an extensive literature on producing carbon black see for instance Donnet, Jean-Baptiste, ed. Carbon black: science and technology. CRC Press, 1993. 

Instead of adapting the Roman recipe for producing lamp black explained on page 19, I would use olive oil rather than resin or turpentine (that is quite a nasty substance). For doing it on a small scale maximizing the yield maybe I would try (under the fume hood)  to heat the oil in a flask attached to a water-cooled Liebing condenser after reaching the smoke point the soot should start to accumulate on the walls of the condenser. It should be quite easy to recollect the carbon black from the wall of the condenser with nylon bristle and maybe from a little funnel with a slight offset fixed on the exit of the condenser. All this should be carried out using heat-resisting glassware in a lab under the supervision of an adult.

P.S.


  The highest percentage I would like to test is 10% soot and that calls
  for around 50 g of it.


This means that you will need more than 50 g for the whole experiment so if you test 10 different proportion you will need at least 80 g performing the experiment only once. It could require a lot of oil to produce 80 grams.