Originally Posted by wilserbrewer
Or dark DME if you can get it...caramel and chocalate malts will boost gravity but not fermentables if I recall correctly.
That's correct. Specialty malts as a rule add very few fermentables. How to Brew by Palmer discusses this.
If you're always getting low OG, you can fix it two ways;
Cover it up by adding more grain, extract, or sugar when you brew.
Solve the root cause of your low efficiency (grain crush, mash temp management, water pH and composition, etc.)
Since you appear to be done the brew, adding more grain is out. Adding sugar will add gravity points, but it will come at the cost of flavour and body. Adding extract is probably a better option, but make sure it's also sterilized before adding to the fermenter.