Stars of the Lid elaborated on the album's reasoning on its inner sleeve.
The merging of color and sound is something we've thought about quite often. Why should the visual artist be confined to the packaging while the "musician" is in charge of the rest - especially when both dimensions may reflect back onto each other. We wanted to craft a sound environment that is both true to Jon's painting as well as the larger New York context which envelopes [sic] his work.
The album was generally received well by critics. John Bush, writing for Allmusic, stated:
Per Aspera Ad Astra is an intriguing 1998 collaboration between tone-generating minimalists Stars of the Lid and line-drawing minimalist Jon McCafferty. The recording was created with plenty of McCafferty's work around for inspiration (and incorporated environmental samples of him painting), then the sleeve was prepared by McCafferty once he'd immersed himself in the album. Separated into two sides, Per Aspera Ad Astra reveals precious little of McCafferty's working habits; except for faint rustlings in the background and passing traffic, the environmental portion is whispery and thin. The concept does allow for a degree of context within Stars of the Lid's music, though, always a good thing when a recording is as ambient and ephemeral as this. Deep and warmly atmospheric, with (per usual) few nods toward traditional instrumentation, the pair focus on indie-space music except at the beginning of side two, when a string section provides a brief interruption.