To provide a data compression controller, a data compression control method, a printing information forming device, a printing system, and a recording medium in which program is recorded which compress or do not compress data on the basis of a variable 'threshold' according to the contents of data to be sent and characteristics of peripheral equipment which receives the data.

According to the contents of data to be sent and characteristics of peripheral equipment which receives the data, the 'threshold' as a criterion for data compression and noncompression is varied. For example, when the amount of the data to be sent is small, the 'threshold' is set high and only when high compressibility is obtained, the data are compressed and transmitted. When the amount of the data is small, on the other hand, the 'treshold' is set low and the data are positively compressed to shorten the transfer time.