Hi everyone!
Let me share with you how I got here. I’m sure some of you will have a giggle or two.
I want to be able to publish my own websites in the future and to do that properly you need a lot of skills these days. I was focusing on learning HTML and SEO and thought ‘how hard can it be to make a simple text logo in various dimensions’, well that might be my worst miscalculation this year.
I only had Gimp since I didn’t even know the difference between raster & vector based software 3 days ago so I designed a simple text logo with a diagonal line under it at 3000 x 2000 pixels. Probably way too big but someone once told me you need to make it bigger than you need it for the best results.
Before I filled the background with black to continue and create my biz card design, I merged the text and line layer, auto-cropped the new layer and exported that as a png to use as a website logo with a 50-pixel height.
After filling the background and saving it at 3000 x 2000 pixels, I noticed Vistaprint asks for a 1040 x 685 document so I scaled it to 1040 x 693, keeping the aspect ratio and expecting to lose a little bit at the top and bottom and saved it again.
Next, I opened both images on my laptop and that’s when my misery began. I noticed the smaller one didn’t look sharp to me from viewing distance although the image was displayed at 100%.
I looked for help online and people explained how I was better off using vector editing software because I could make one design and resize, rotate, do whatever I want with it and it will still look good. However, they also said you could use raster editing software too if you create the image at 100%, the size it will be used.
So eventually, I re-created everything in Inkscape and you could say that my problem is solved, but what I’ve been told contradicts what I have experienced with Gimp and I just can’t let it go, I need to get to the very essence of this and fully understand it before I can continue life 
