Air-stable semiconducting inks suitable for complementary logic are key to create low-power printed integrated circuits (ICs). High-performance printable electronic inks with 2D materials have the potential to enable the next generation of high performance low-cost printed digital electronics. Here, the authors demonstrate air-stable, low voltage (<5 V) operation of inkjet-printed n-type molybdenum disulfide (MoS2), and p-type indacenodithiophene-co-benzothiadiazole (IDT-BT) field-effect transistors (FETs), estimating an average switching time of τMoS2 ≈ 4.1 μs for the MoS2 FETs. They achieve this by engineering high-quality MoS2 and air-stable IDT-BT inks suitable for inkjet-printing complementary pairs of n-type MoS2 and p-type IDT-BT FETs. They then integrate MoS2 and IDT-BT FETs to realize inkjet-printed complementary logic inverters with a voltage gain |Av| ≈ 4 when in resistive load configuration and |Av| ≈ 1.4 in complementary configuration. These results represent a key enabling step towards ubiquitous long-term stable, low-cost printed digital ICs.