don't understand something about backslashes

I have a varchar that is 64 wide. I prescape stuff like the '-'
character to prevent SQL injection.

Here is the EXACT field value that I inserted recently,for a test. It
comes to approx 100 chars.

'\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1\-1'::varchar,

I insert that and get:

NO ERROR

When I look at the record in phpPgAdmin, the slashes don't show up in
the record.

So, do they make it to the record, anyone know? What do I have to do for
the PostgreSQL engine to prevent '--' character from ending a line in a
a string? Or in general, get the backslashes in the record?