how do it make the printer print brighter photos and letters - have a Canon printer?

The paper you use, and setting the printer to use that paper, will make all the difference in the world. Standard "copy" paper is crap, and there is nothing you can do to make it look good.

You don't need glossy photo paper for anything but photos, but there are many brands of paper that will give you better results even for text printing. Yes, this costs more than copy paper, but the results are absolutely worth it if you care what your prints look like.

An office store can help you find bright white inkjet paper, which is heavier than copy paper and much closer to white. This is the paper to use for text and spot color printing. For photos, stick with photo papers, although I prefer semi-gloss over gloss for photos. Purely personal choice there, both work well.

Once you find a paper you like, you have to tell the printer (through the driver) what sort of paper you have. The printer will then adjust the output for the paper, giving the best possible results. Do not forget to change the setting if you change the paper! Improper paper settings will give you terrible prints, many times they will be worse than just using copy paper.

To make it easy, Canon has a full line of papers for their printers, however none of them are "cheap". HP and Epson also carry full lines, and you can use them too. I have a large stock of Hammermill brand "Color Copy Digital" 28 pound paper, I use in both inkjet and color laser printers. This is good for almost everything except actual photos, for that I use Epson Luster or Costco brand glossy photo paper. The Epson stuff is for large prints, up to 17x22", while the Costco gets used for standard paper size prints.

Uses a good grade of photo paper. In your printer settings

Select Best, or at least Normal.

Use photo paper for photos