Draw to whole stack

I am trying to use the paintbrush tool to draw something that I need to appear on all the images in the imported stack. However, it only draws to the currently displayed image. Is there a way to get what I draw to be on all the slices?

Try using the ‘Pencil’ tool. Double click on the pencil tool and make sure you select ‘Paint on overlay’ and then try. It should work on the whole stack now.

1 Like

Please note that painting on the overlay appears in all slices, but it does not paint on the image data, as the “normal” brush. Actually the image data is unaffected.

1 Like


This is exactly what I want to do: to affect the images of my whole stack with the overlay brush… Which I cannot do because of the way this tool works…
Any Idea of how to merge the overlay to the stack?
Or maybe how to select, copy and paste the drawing made with the normal brush on one image to the whole stack?


Hi Sara, when I use the overlay brush I see the overlay on every image in the stack and I can flatten it (ctrl+shift+f) to every image or a single image by choice. If, on the other hand, I use the regular paintbrush the pixel values are changed directly, this is not an overlay and will only appear on the one image.

Are you sure you are using the overlay brush? Go to More tools image and select Overlay Brush.

EDIT: I see that the regular brush has a “paint on overlay” toggle, an overlap in function apparently… but it lacks the transparency setting. And color selection menu.

Right double click on the icon to open the settings window.


1 Like

Whereas right-clicking on the Paintbrush Tool brings up the settings dialog, it doesn’t do anything for me on the Overlay Brush Tool. Double-clicking works for both.

1 Like

Thanks both for your answer.
I indeed use the overlay brush, or the regular brush with the option “paint on overlay” selected and I can indeed “see” the modification on every image of the stack BUT it doesn’t affect the pixels of the images. It is just…well… an overlay… :wink: By just inverting the images, I see the overlay in the initial color.
What I simply want, is to delete a feature which is located on every images by coloring it with the background color.
I work with 8bit binary images.

As Sverre Grødem wrote:

Flatten the overlay.

BTW, what image feature are you trying to delete?



Indeed Herbie…

It perfectly work with the tool flatten

I want to erase an artefact for betterave visualisation