What is a BLKRT file?
BLKRT is the file format used by Block Artist. It is a proprietary format belonging to the raster group. Block Artist is an image creating and editing software available for Windows users back in the day. It is now considered obsolete and unsupported.
How to Make BLKRT Files
Exact steps for creating BLKRT files will vary by program and operating system. Download one of the above listed programs and you should be able to follow typical procedure for opening files or creating files from the File menu. Typically you will select File > Open or File > New and continue through the prompts. Some programs may follow a different procedure for either creation or opening of files.