The article describes the development and application of a complementary transposon tool kit for *Drosophila melanogaster* using the P-element and piggyBac transposons. The authors aimed to create a complete gene knockout collection, which required generating and analyzing up to 150,000 insertions to achieve 87% saturation of the *D. melanogaster* genome. They improved the efficiency of transposon mutagenesis by incorporating three technological advancements: using piggyBac as an additional mobile genetic element, constructing vectors with 'splice-trap' and transcriptional silencing elements, and focusing on the female germ line to alter the spectrum of genes accessible for tagging. The study generated over 29,000 piggyBac and P-element inserts, resulting in 53% gene saturation. PiggyBac was found to have distinct global and local gene-tagging behavior compared to P elements, with nearly precise excisions from the germ line, no chromosomal hotspots, and more effective gene disruption due to its lack of bias for inserting into 5' regulatory sequences. The authors observed higher frequencies of recessive lethal mutations for both piggyBac and P elements, which were not due to multiple insertions or background mutagenic effects. The insertions were distributed across the genome, with piggyBac inserting more frequently between transcriptional start and stop, creating null alleles more commonly. The combined piggyBac and P-element collection tagged 53% of the Drosophila Gene Collection genes, making it a useful resource for gene function analysis in pharmaceutical-relevant disease pathways. The reagents and transposon tool kit will complement existing *D. melanogaster* gene knockout resources.The article describes the development and application of a complementary transposon tool kit for *Drosophila melanogaster* using the P-element and piggyBac transposons. The authors aimed to create a complete gene knockout collection, which required generating and analyzing up to 150,000 insertions to achieve 87% saturation of the *D. melanogaster* genome. They improved the efficiency of transposon mutagenesis by incorporating three technological advancements: using piggyBac as an additional mobile genetic element, constructing vectors with 'splice-trap' and transcriptional silencing elements, and focusing on the female germ line to alter the spectrum of genes accessible for tagging. The study generated over 29,000 piggyBac and P-element inserts, resulting in 53% gene saturation. PiggyBac was found to have distinct global and local gene-tagging behavior compared to P elements, with nearly precise excisions from the germ line, no chromosomal hotspots, and more effective gene disruption due to its lack of bias for inserting into 5' regulatory sequences. The authors observed higher frequencies of recessive lethal mutations for both piggyBac and P elements, which were not due to multiple insertions or background mutagenic effects. The insertions were distributed across the genome, with piggyBac inserting more frequently between transcriptional start and stop, creating null alleles more commonly. The combined piggyBac and P-element collection tagged 53% of the Drosophila Gene Collection genes, making it a useful resource for gene function analysis in pharmaceutical-relevant disease pathways. The reagents and transposon tool kit will complement existing *D. melanogaster* gene knockout resources.