There are cases in which it's very important create a perfect symmetry in the illustration we are creating in order to balance perfectly the weight of the image, without visual and "psychological" effects that can make the image unpleasant to the sight.
As you can see, the cross is much work and I wanted to be sure that "cutting" the image, it could be perfectly symmetrical.
Here's how I solved.
In gimp an other softwares there is the opportunity to flip the image...I usually use an old program, Micrografx Picture Publisher, but every software do what I'll say.
We can take as example a cross:
- Take a sheet of paper and pencil and draw a simple cross without details.
- Made this first cross, cut it with a line to have, for each segment, half of the central body and an arm of the cross.
- Developed a segment as you prefer. Recrossing the contours with a pen, clean the sheet of paper with a rubber and the scan image.
Now the steps to do with your computer.
- Open the image with "microsoft office picture publisher", adjust the Midtones to "-100" and saved. In this way you can see better your half cros (scanning can impoverish the colors of your pictures but, in this way, you will recover them).
- Open the illustration with your graphics application. Clean another time your illustration and select the portion of the cross that you created, if required, transform it into a mask and flip it horizontaly (be sure the background color of the selection is transparent), and overlapping the outermost points of the two half cross to obtain the perfect symmetry.
- Obtained the symmetry, add the mask to the rest of the image and you have created an object perfectly symmetrical, that you can paint and transform as you prefer.
You can apply this technique to any object, not only crosses but also, for example, spiders, butterflies, on human bodies and so on ...
The only difficulty that this method of work can pose is working on half object: if you don't have the clear ideas about the final result, you risk losing time for anything!
I hope that this advice can come in handy! :-)