Polish Handwritten Characters Database (PHCD) is available for download
and use free of charge. Database consists of over 530,000 images of
handwritten characters — about 6,000 images for every character.
More information: http://www.astrj.com/Development-of-Extensive-Polish-Handwritten-Characters-Database-for-Text-Recognition,122567,0,2.html
Download: https://cs.pollub.pl/phcd/phcd.rar