I had a problem with this at first. How do you make a 72 dpi photo into a 300 dpi photo? I figured it must be impossible, but after asking for advice online realised you could do it with PhotoShop. Expensive? It could be...
Cue GIMP, short for Gnu Image Manipulation Program, which is free to download and use.
Go to GIMP now and download it. I'll wait here for you.
Back so soon? I knew it wouldn't take you long. OK...
This is how to make your images hi-res:
1. Open GIMP
2. From the menu at the top, click on file > open, then browse and open your image from the files on your computer
3. When you have your image in front of you, use the menu at the top again: click on image > scale image and a box will open.
4. In the box you'll see the X and Y resolutions are both set to 72.000 pixels/in (pixels per inch or dots per inch). Change these to 300.000 then click the scale button.
5. It looks like nothing has happened! But it has - so save your newly-altered hi-res image in a new file.
Note: There are different endings you can use for your file name. GIMP likes to save them as .xcf files so you can alter them using GIMP again. It's better saving them as .jpg files as everyone can open these, no matter what programs they use. There is an option to save your files in different formats at the bottom of the save as box (click select file by type and choose the .jpg option)
Your new hi-res image is now ready to send to a magazine. Yay!
You won't be able to attach many of these to an email as they're so big and may have to send only one at a time. But they will only ever be sent on request when needed for print (never send a hi-res image on spec) so it's unlikely they'll need more than a few at a time anyway. If they do, you can use a free file transfer service such as We Transfer - it's really quick and easy to use and you get an email telling you when your images have been downloaded at the other end.
I'd recommend having a separate file on your computer for your hi-res 300 dpi images then you'll know exactly where to find them when you need one at short notice - and they won't get mixed up with your low-res images. And back up your images!
If you missed the post last week about how to get your handmade products featured in a magazine, have a quick look now. It's only a click away.