1. Not all black inks contain the same pigments. The black inks that are made up of more than one pigment are a combination of different colors. 2. Our purple ink appeared to be a single pigment. Different solvents of purple could be tested to see if they also have one pigment like our purple did. After many different purples compare the results. 3. It is necessary to keep the water level below the ink spots because the water will move up the beaker and bring the pigments with it. 4. It is important to cover the beaker so moisture doesnt get into the beaker. It is important to not jostle the breaker because when you move the beaker the water moves to messing up the pigments. 5. You could take several dyes with different affinities to the same liquid then compare them after the paper chromatography experiment. To determine the presence of a specific dye you could make a chromatograph of the specific dye and compare it to the chromatograph of a die that is suspected to have the specific dye in it.