I need to cut out the drawn violin plot in the way that only the outside line exists and the rest (the inner body) is transparent, because I have to fit the plot over some points (points should be still visible underneath the plot.
Has anybody recommendations or ideas for how that would work out?
By default, the violin plots should be transparent like this:
I can see the points in spite of the shading.
However, you can put in an outline and remove the shading. To do this, right-click on the graph and choose Customize. You should see a dialog box that lists all of the violins in the graph. For each one click the Fill Pattern and select the empty fill. Click the Line Color and choose the outline color that you would like. I did this just for the Age 12 people to show the look.
The customize dialog that @Dan_Obermiller refers to may have other options that you will find useful as well. It sounds like you might be using Copy Frame Contents and Paste Frame Contents to move the violins into another graph. When you do this, the violins will be layered on top of whatever is already there. From the customize dialog you can also:
1) Change the layering of the objects (arrow buttons). Move the violins up in the list to have them drawn before the points.
2) Change the fill color of the violins - in the source report the color was likely linked to a legend, so they may lose their color when copied.
3) Change the transparency - For a different effect, using transparency would also make points beneath the violin visible.