If all you want to do is apply a solid colour to your 3D object or to certain faces of your 3D object then see the 'materials' page, not this one. If you want to be able to have more freedom in your painting, then 3D painting is a good option - it lets you paint as if you were using a paintbrush or airbrush. But are you sure you want to do this with the Blender render engine? The Cycles render engine is vastly superior so I recommend you stop reading this page immediately and learn instead how to 3D paint with the Cycles render engine! If you have some weird reason why you want to use the inferior Blender render engine then read on...
There are two ways to paint your 3D object. In both methods you must first 'unwrap' the surface of the object, which is process comparable removing and flattening the peel of an orange. Unwrapping involves making 'seams' in the surface, possibly such that the unwrapped image shape will have multiple parts. Knowing how to unwrap well is quite an art!
- Once the surface has been unwrapped and flattened (just like your flattened orange peel) it can then be exported into a specialized painting program such as Photoshop, Paint Shop Pro or the GIMP, worked on there and then imported back in again. A problem with this method is that it is necessary to choose the seams carefully where the different parts of the surface will be separated from one another. This method is not explained in this site so if you would like to try this method please check the Blender online manual or one of the many tutorials available on the internet in places like YouTube.
- Alternatively you can paint directly inside Blender using a combination of Texture Paint mode in the 3D view editor window and Paint mode in the uv/image editor window. This method is intuitive and there is no problem with seams as in the first method. This is the method explained below. IMPORTANT: when you do UV unwrap you create a 2D (flat) image that won't necessarily be saved when you save your Blend file so there is a risk that you may lose the image. There are two ways of making sure you don't lose your image. Whichever method you use you should use after you have finished modifying the image since otherwise you will lose later modifications to the image.
- Save the uv image by choosing Image>Save as image in the menus under the uv image editor window or by pressing F3. If you make any changes to the image you will need to save it again.
- Pack the image into the Blend file by choosing Image>Pack as PNG. Then when the Blend file is saved it will include the image. If you make any changes to the image you will need to re-pack the image.
Warning: the video below uses the Blender Render engine which is now obsolescent since a much better render engine called Cycles is now available. Click HERE to learn how to do 3D painting in Cycles. If you absolutely want to learn how to paint using the old Blender Render engine then watch my 19 minute Vimeo video below. Better yet, you should watch it on Vimeo (click the HD button) because then you can watch in HD and because you can jump around within the video which may not work with the embedded video below.