Wow that was painful! I downloaded Picasa, Paint.net, and Snagit all to no avail! I ended up just using PowerPoint to "collage" my images, gave them a boarder, grouped them and then saved the grouped image as a picture. Then I went to http://www.image-resizer.eu as suggested above, uploaded the picture, changed the pixels to 8100x5400 (keep it in JPEG or it will be too big to load on Spoonflower....trust me, I know), and downloaded the re sized image to be uploaded to Spoonflower. I was a little nervous because when I clicked on "center" as my option for the fabric, it was only showing part of my image. Then I realized it was only showing part of the ruler as well (I'm blonde). If you hit "zoom" under the preview, it will show you the whole thing. I'm about to order, here's hoping it looks ok!! :)