Much as the title says, any current recommendations for filter frames for Wratten gels - preferably both in 75x75mm and 100x100mm sizes? Ideally ones that don't require trimming of the filters. Mainly for darkroom use, so don't need to be super fancy, just durable and reliable.
The cardboard self stick "mounts" were made to fit in the metal frames. Lee makes a holder for their 4x4 polyester filters and Cokin makes a holder for 75x75mm gels (tha would be P system probably).