First a bit about the files:
They are high resolution and saved at 300 dots per inch - which is really important for quality printing. Files from Playful Pixie Studio will have the size of your file at the end of the file name, ex. "printable-8x10.jpg", the "8x10" placement is where you will find the size. If you downloaded from Corjl there will be a string of digits after the size, ex "printable-8x10_178ddkjea89j_akjid13553_1.jpg".
IT IS NOT RECOMMENDED to print larger than the size displayed, as prints start to look grainy and pixelated if printed too much larger than their intended size.
Files and where to print them:
JPG files are best for printing from home or photo labs (like Walmart, VistaPrint, FedEx).
PDF files are best for printing from print shops (like Staples).
PNG files can be used for sublimation or printing on physical items, please remember these won't work as cut files or in cutting machines, such as Cricut or Silhouette.
Tips for printing from home:
There are several factors which can vary results of your print when print from home. First, make sure your print quality is set to "Best". Also, check that the type of paper and size you are using is selected (ex. photo paper, 4x6), if that option is available on your printer.
Other factors that can change your print is if the printer's ink level is low. When the ink is low it can make prints look awkward in a lot of different ways. The type of paper can also change the way your photo looks. For instance, if using regular printer paper, a photo may print out with lines because this type of paper is better suited to text as it absorbs ink differently than photo paper or card stock.
Paper recommendation:
A heavyweight paper or card stock of 110lb. with a matte finish will give you beautiful results. *Side note - in general, you won't be able to choose your paper type from a photo lab, only the finish. Options are usually glossy or matte. I prefer matte because it will hide things, like fingerprints. And trust me, I've seen my share of glossy images with fingerprints (it's not pretty).
