I am working with TGA and blendFunc, when I load an image with alpha channel and 32 bpps the image has a poor quality, but loading the same image without alpha channel and 24 bpps the quality is perfect. I don''t know why. Here is a link to an image Top: TGA without alpha channel 24bpps Bottom:TGA with alpha 32 bpps http://www.geocities.com/opengladiator/imagenes/img.jpg To load TGA I use: glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, m_ancho, m_alto, 0, GL_RGB, GL_UNSIGNED_BYTE, m_imageData); or glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, m_ancho, m_alto, 0, GL_RGBA, GL_UNSIGNED_BYTE, m_imageData); and for blend glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);