... posted: 17 Sep 2010 18:22 from: Martin Wynne Hi Brian, I would really like to clear up this problem of dithering and colouring. I suggest that you download a copy of Irfanview -- it's free. From: http://www.irfanview.com I modified your tank drawing to illustrate a non-rectangular image with transparent background. 1. save from Visio in BMP format. 2. then open the BMP file in Irfanview. 3. and click Save As... This is the Irfanview screen: 2_171254_390000000.png 4. select to save in GIF format and view the options dialog on the right. 5. on the options dialog, set the GIF options to save in transparent format and to choose the transparent background area. When you click Save, you are invited to click the area/colour which is to be made transparent, like this: 2_171253_580000000.jpg 6. I clicked the white area top left. Any area of white colour anywhere in the image will then display transparent. Here's the result: 2_171305_160000000.gif The image details look ...