One stupid graphic design questions

Hey I have started a youtube channel: it is vine compilation channel

If you have seen any vine compilation channel you might have seen them using custom background image in videos. I have made that one but I am getting the quality of the image to the professional level. I have used canva.com to design background. I made the image size 2048x1024px but still I am not getting it.

Can you please suggest me the right size or anything, any clues get it done. Current problem is I don't get the text on the image look good in the video even though they look like good typography in the image.

Hope I find a solution here.
Thanks

Hey some one please answer this. Thanks

If your image looks fine, it sounds like the problem is your video quality, try bumping that up when you create the video.