I have not mastered vinyl myself, but in the days that I released on vinyl, records were mastered to conform to the RIAA equalization curve, which cuts the record with greater highs and less lows, then inverts them on playback. I copied this explanation from a Wikipedia entry (http://en.wikipedia.org/wiki/RIAA_equalization
IAA equalization is therefore a form of preemphasis on recording, and deemphasis on playback. A record is cut with the low frequencies reduced and the high frequencies boosted, and on playback the opposite occurs. The result is a flat frequency response, but with noise such as hiss and clicks arising from the surface of the medium itself much attenuated. The other main benefit of the system is that low frequencies, which would otherwise cause the cutter to make large excursions when cutting a groove, are much reduced, so grooves are smaller and more can be fitted in a given surface area, yielding longer playback times. This also has the benefit of eliminating physical stresses on the playback stylus which might otherwise be hard to cope with, or cause unpleasant distortion.
A potential drawback of the system is that rumble from the playback turntable's drive mechanism is greatly amplified, which means that players have to be carefully designed to avoid this.
RIAA equalization is not a simple low-pass filter. It carefully defines transition points in three places - 75 Ás, 318 Ás and 3180 Ás, which correspond to 2122 Hz, 500 Hz and 50 Hz. Implementing this characteristic is not especially difficult, but more involved than a simple linear amplifier. The phono input of most hi-fi amplifiers have this characteristic built in, though it is omitted in many modern designs, due to the gradual obsolescence of vinyl records. A solution in this case is to buy a special preamplifier which will adapt a magnetic cartridge to a standard line-level input, and implement the RIAA equalization curve separately. Some modern turntables feature built-in preamplification to the RIAA standard. Special preamplifiers are also available for the various equalization curves used on pre-1954 records.
Digital audio editors often feature the ability to equalize audio samples using standard and custom equalization curves, removing the need for a dedicated hardware preamplifier when capturing audio with a computer. However, this can add an extra step in processing a sample, and may amplify audio quality issues of the sound card being used to capture the signal.
Congrats on your vinyl release, Martin!