There are 42 Origami Designs in CDO convention 1990:

Design	Designer	Page	Details	Photo
Show only designs with photos
Regular heptagon Geometric and other shapes	Humiaki Huzita	1	Square
Pentagon letter Letters and Envelopes	Humiaki Huzita	4	Rectangle - A size
Portfolio Objects - Useful	Humiaki Huzita	6	Rectangle - A size
Chinese vase Boxes and Containers	Traditional	8	Square Also in NOA Magazine 543 Also in Origami A-B-C by David Petty Also in Paper Magic by Paul Jackson Also in The Ultimate Papercraft and Origami Book by Paul Jackson and Angela A'Court Also in Orison 20/04 Also in BOS Convention 1990 Autumn and in other sources... Verdi's vase	Folded by Gabriel Vong
Rose Flora - Flowers	Martin David Kruskal	9	Square
Aurora Geometric and other shapes	David Mitchell	10	Square 30 units
Purse module Geometric and other shapes	David Petty	11	Square With variations
St. Nicholas envelope Letters and Envelopes	David Petty	24	Square
Easy top vase Boxes and Containers	David Petty	26	Square
Butterfly Insects - Butterflies	Nick Robinson	28	Rectangle - A size Also in BOS Convention 2003 Autumn Also in BOS Magazine 141 Also in Origami USA Convention 1989 Also in The Best of Annual Collections 1981-1995 Also in The Origami Bible by Nick Robinson	Folded by Gilad Aharoni
60 degree sunken unit Geometric and other shapes	Nick Robinson	30	Hexagon
Tray Boxes and Containers	Nick Robinson	31	Square Also in BOS Convention 1988 Autumn Also in Origami USA Convention 1991 Also in Pajarita Magazine 24 Also in Papiroflexia Basica by Vicente Palacios	Folded by Wilson Yeung
Adjustable belt Clothes - Clothing Accessories	Nick Robinson	32	Rectangle - Long strip
Mouse - white faced Mammals - Rodentia - Rats, Mice and Rodents	Robert J. Lang	33	Square Also in The Complete Book of Origami by Robert J. Lang	Folded by Nicolas Terry
Teapot Food	Martin Wall	34	Square
Cup with handle Food	Martin Wall	35	Square
Shovel or scoop Objects - Various	Martin Wall	36	Square
Hobby horse Toys	Martin Wall	37	Square bookmark
Dragon Imaginary beings - Dragons	I. Zuber	38	Square
Star tessellation Geometric and other shapes	Sonia Amadori	40	Triangle Multiple units
Bow Toys - Planes	Maximilliano Calleri	41	Rectangle
Coasters Geometric and other shapes	Silvana Betti Mamino	42	Square 8 units
Flower Flora - Flowers	Paola Galtineri	43	Square
Rectangular box Boxes and Containers	Paola Galtineri	44	Square
Modular star with variable diameter Geometric and other shapes	Enio Capra	46	Square 8 units
Lapwing Birds - Charadriiformes - Gulls	Donatella Cecconi	48	Square
Envelope with fins Letters and Envelopes	Donatella Cecconi	50	Square
Octagonal box Boxes and Containers	Donatella Cecconi	51	Square
Butterfly 1 Insects - Butterflies	Antonio Coiana	52	Square 2 units
Butterfly napkin fold Insects - Butterflies	Antonio Coiana	54	Square 2 units
Concave prism Geometric and other shapes	Antonio Coiana	55	Square
Ashtray Boxes and Containers	Emma Frigerio	56	Square
Butterfly Insects - Butterflies	Alfredo Giunta	58	Square Also in A Arte dos Mestres de Origami by Mari Kanegae Also in Divertitevi con L'Origami (Enjoy Origami) by Alfredo Giunta Also in NOA Magazine 200 Also in Origami Masters: Alfredo Giunta by Alfredo Giunta Also in Quadrato Magico Magazine 26 Also in Zoorigami by Renzo Zanoni and in other sources...	Folded by Gilad Aharoni
Guillotine Objects - Weapons	Luigi Leonardi	60	Square 4 units
Executioner People - Occupations	Luigi Leonardi	68	Square
Decapitated convict People	Luigi Leonardi	71	Square
Zappa Objects - Various	Luigi Leonardi	72	Rectangle
Supersonic plane AR Z10 Toys - Planes	Franco Pavarin	74	Square
Supersonic plane AR Z20 Toys - Planes	Franco Pavarin	78	Square
Envelope Letters and Envelopes	Luciano Petino	83	Rectangle - A size
Ashtray Boxes and Containers	Luciano Petino	84	Square
Tropical fish Fish	Luciano Petino	87	Square