Science Buddies: "Ask an Expert"

I'm now working on a school science project and mine is about comparing the the cleanliness of clothes after using stain removers of difference brands. My problem is, I couldn't find out a way to measure the clothes' cleanliness numerically. If anyone would help, I'll be very appreciated. Thank you.

Hi Jenny and welcome to scibuddies! We'll be happy to try and answer your questions.

It sounds like you are trying to compare the effectiveness of several stain removers and would like to have a method for quantitating the results. As the stain remover works, the stain should get lighter and this change from dark to light can be analyzed using a free program called ImageJ (https://en.wikipedia.org/wiki/ImageJ) which you can download from the National Institutes of Health here: https://imagej.nih.gov/ij/download.html

To measure the darkness of a stain you would photograph it and upload the image to your PC (after you downloaded and installed ImageJ). The program has several tools for quantitating intensity of an image area and that is how you obtain a numerical value for the density of a stain. After using a stain remover, you would photograph the stain again and measure its intensity. The reduction in density of the stain would be a measure of the effectiveness of the stain remover.

You will need to learn how to use ImageJ but it isn't hard. Here's one set of instructions in a pdf doc: https://www.unige.ch/medecine/bioimagin ... cation.pdf

I like to see and hear about a technique so I like Youtube videos for this. There are several that show how to use ImageJ to quantitate the intensity of specific areas in a jpeg image: https://www.youtube.com/results?search_ ... use+imagej

For comparing before and after images, I was just thinking that it might be better to scan the stain rather than try to photograph it because the lighting will be more constant with a scanner. Most printers in use today have scanners built into them which will give you a jpeg image that you can then load into ImageJ and quantitate.

Post again if you are interested in using this method and we can help you with the details.

Sybee