I have some problem with database size.

I have an table with a blob field ( i use firebird ) .
I have to insert a .RTF file into blob field. So i have read file .RTF into an array of bytes, then insert it into database.
But the problem is the size of []bytes so large.
Is there anyway to reduce the size of database .
Is there anyway to compress file before insert

Please help me !

Regard !