High resolution Photoshop Brushes found on Heygrey.com site are .abr files which is standard Photoshop Brush collection file. Brushes vary in size from 100 x 100 pixels up to 2500 x 2500 pixels.
Brushes have been tested with Photoshop CS3 and Photoshop CS4 versions. If you have some other version then we strongly suggest first to download sample brushes to see whether they work on your computer and only then make the purchase. Heygrey.com does not offer any refunds. (Please read the Terms for further details)
It is advisable that you use the size which does not require any reduction or enlargement. Even though Photoshop has nice and easy-to-use functionality for resizing, the quality of the work might suffer as a result of resizing. Brushes provided by Heygrey.com have been one-by-one optimized for each particular size.
Of course, with little knowledge and extra work you can achieve the same quality results also yourself if you use as a basis the largest version of the brush. We simply have done this work for you in case you decide to choose a brush collection of all the sizes available.
If you have difficulties installing the brushes, then please check Photoshop Help pages about Loading, Saving, and managing brush presets or just run a search on net for numerous step-by-step guides on how to do that. It's quite simpe!
If you have any further questions then please feel free to contact us.