Retrieval is a fundamental task in multimodal systems: given an image or text query, the goal is to find the most relevant images or texts in a collection, often using a shared embedding space. Reliable retrieval requires these embeddings to capture not only which concepts are present, but also how they are composed. One key compositional challenge is attribute--object binding: encoding which attributes belong to which objects. Existing benchmarks provide a limited view of this capability, typically covering a subset of modality pairings, simple two-object swaps, or small attribute sets. Consequently, it remains unclear how robustly current models preserve attribute--object bindings across different modality pairings and more complex settings. We therefore introduce SABER, a controlled benchmark for evaluating attribute--object binding across all four image and text modality pairings, spanning diverse attribute types and scenes with up to ten objects. Evaluating models on SABER reveals substantial binding failures in both CLIP-style dual encoders and recent MLLM-based embedders. These findings motivate us to ask how binding can be improved efficiently. While multimodal supervision may be effective, collecting suitable images is difficult and costly. Text, on the other hand, is well suited to binding supervision: it is cheap to generate, supports a broader range of attributes and enables precisely controlled hard negatives. We thus finetune an MLLM-based embedder exclusively on synthetic attribute-binding text. Despite the absence of image supervision, the gains transfer to cross-modal and image--image retrieval while preserving general multimodal embedding performance. Our model achieves SOTA results on SABER while also improving on negation and instance-retrieval benchmarks, demonstrating broader benefits of our binding-focused supervision.
Figures & tables
Figure 1: Overview. Top: SABER evaluates attribute–object binding by reassigning fixed sets of objects and attributes. Bottom: Synthetic text-only finetuning improves binding in text and image representations, boosting unimodal and cross-modal retrieval on SABER and existing benchmarks
Figure 2: SABER multiple-choice questions. Each query has four candidates with 2–10 attribute–object pairs: one preserves the bindings, while the others form hard negatives by reassigning attributes. For two-object examples, one negative instead replaces an object or attribute. Although only images are shown, the accompanying captions enable evaluation within and across modalities.
Modalities
Evaluation Method
Benchmark Statistics
Dataset
T → T
T → I
I → T
I → I
MCQ
Retrieval
# Eval. Samples
Object Vocab.
Attribute Vocab.
# Bindings / Sample
NCD
×
×
✓
×
✓
×
1,998
19
6
2
VG-Attribution
×
×
✓
×
✓
×
28,748
open
open
2
ColorSwap
×
✓
✓
×
✓
×
1,000
open
open
2
SugarCrepe-Swap-Att.
×
×
✓
×
✓
×
666
open
open
2
SugarCrepe++-Swap-Att.
✓
×
✓
×
✓
×
666
open
open
2
Table 1: Existing attribute-binding benchmarks. Open denotes an unrestricted vocabulary; MCQ includes Winoground-style 2×2 matching and SugarCrepe++’s three-caption evaluation.
Figure 3: Nested SABER chains. Nine linked MCQs form a chain from two to ten objects, read left to right and top to bottom. Each successive query adds one binding while preserving all earlier ones. Half of SABER’s MCQs are organized into such chains, allowing later correct candidates to serve as additional positives for earlier queries in large-gallery retrieval.
SABER-MCQ
SABER-Retrieval (Independent)
SABER-Retrieval (Nested)
Model
T → T
T → I
I → T
I → I
Mean
T → T
T → I
I → T
I → I
Mean
T → T
T → I
I → T
I → I
Mean
CLIP ViT-B/32
53.6
23.0
22.3
75.5
43.6
74.0
38.8
33.1
85.1
57.8
38.0
13.7
16.1
49.3
29.3
LABCLIP ViT-B/32
55.2
22.8
24.2
75.3
44.4
74.3
35.0
25.8
85.1
55.0
38.1
13.0
12.1
49.2
28.1
TripletCLIP ViT-B/32
42.9
27.1
22.2
60.2
38.1
65.9
8.8
5.0
63.2
35.7
35.8
5.4
3.5
32.1
19.2
READ-CLIP ViT-B/32
47.3
23.9
23.7
82.3
44.3
68.4
33.5
23.6
89.7
53.8
37.7
10.7
13.1
54.1
28.9
PE-Core-bigG-14-448
66.1
29.7
27.6
67.6
47.7
81.1
56.0
55.5
81.5
68.5
41.5
23.6
32.9
47.1
36.3
Table 2: Performance on SABER. SABER-MCQ reports mean 4-way accuracy (%) and SABER-Retrieval mean mAP (%), both averaged over 2–10 objects. Retrieval is split into independent and nested subsets over the pooled candidate gallery. Our finetuned 8B model performs best across all four modality pairings in both protocols. Results by number of objects are reported in Tables 17 , 18 , and 19 in the Appendix. Best and second-best results are shown in bold and underlined, respectively.
Dataset
CLIP [-1.5pt]B/32
LABCLIP [-1.5pt]B/32
TripletCLIP [-1.5pt]B/32
READ-CLIP [-1.5pt]B/32
PE [-1.5pt]CORE-G
LamRA- [-1.5pt]Ret
Qwen3-VL [-1.5pt]Emb-2B
Qwen3-VL [-1.5pt]Emb-8B
Ours-2B
Ours-8B
Text → Text
SugarCrepe++-Swap-Att.
32.7
41.0
34.7
56.8
53.2
66.2
50.3
70.9
78.7
93.7
Text → Image
ColorSwap
17.9
15.5
14.0
24.5
44.6
23.1
22.8
45.9
34.2
79.8
BiVLC-Swap-Att.
19.1
24.1
7.2
31.7
19.4
21.2
15.1
21.6
16.2
32.0
Image → Text
Table 3: Performance on existing attribute-binding benchmarks. Accuracy (%) under each benchmark’s native multiple-choice protocol. Best and second-best results are shown in bold and underlined, respectively.
Model
Image
Video
VisDoc
Text
Agent
All
# of Datasets
37
18
27 1 1 1 MMEB-v3 reports 24 VisDoc tasks but enumerates 27 ; we score all 27 for every model.
53
47
182
Qwen3-VL-Embedding-2B
69.7
56.3
74.2
40.3
39.8
52.8
Ours-2B
67.7
56.1
73.0
39.7
41.1
52.3
Qwen3-VL-Embedding-8B
73.7
59.6
74.3
43.7
39.1
54.7
Ours-8B
72.5
58.7
75.4
43.1
42.3
55.2
Table 4: MMEB-v3 results. Average Hit@1 is reported for image, video, and agent tasks and NDCG@5 for VisDoc and text tasks. Our finetuned models remain within 0.5 points of their pretrained counterparts overall. Best results per pretrained–finetuned pair are shown in bold.
NegBench coco
NegBench voc
Model
Affirmation
Negation
Hybrid
All
Affirmation
Negation
Hybrid
All
Qwen3-VL-Embedding-8B
78.3
6.8
36.3
41.4
89.9
4.7
58.0
39.8
Ours-8B (negation-filtered)
82.7
6.6
58.1
50.3
91.5
6.4
78.2
49.7
Ours-8B
83.4
6.8
58.5
50.7
91.8
6.1
79.6
50.3
Qwen3-VL-Reranker-8B
80.6
17.8
46.9
49.3
95.0
28.1
58.0
50.4
Table 5: NegBench results. MCQ accuracy (%) by correct-statement type on the COCO and VOC 2007 subsets. Our finetuned model improves overall performance, with the largest gains on hybrid statements. Best results are shown in bold.
I → I
T → I
Model
ILIAS
INSTRE S → S
INSTRE M → S
INSTRE M → S+M
PODS
Paris6K
Oxford5K
Sculptures6K
ILIAS
Qwen3-VL-Emb-8B
58.5
92.8
81.3
75.6
85.7
86.8
61.3
50.8
52.3
Ours-8B
68.4
94.9
86.7
79.0
88.1
88.9
64.3
59.6
60.8
Table 6: Instance retrieval performance. Results report mean mAP (%) across image–image and text–image benchmarks for Qwen3-VL-Embedding-8B and our finetuned model. For INSTRE, S and M denote the single- and multi-object subsets, respectively. Best results are shown in bold.
Appendix figures & tables20 assets
Supplementary material from the paper’s appendix.
Appendix
Attribute category
#
Basic color
9
Other color
2
Metallic
3
Material
19
Pattern
15
Effect
2
Appendix
Table 7: Number of SABER attributes in each semantic category.
Construction type
#
pair_swap
20,000
attr_bundle
20,000
predicative
20,000
triple_bind_cycle
10,048
triple_bind_swap
9,952
deferred_bind_anaphoric
9,417
Appendix
Table 8: Number of finetuning examples by construction type.
pair_swap
Query
wrinkled tunic and cotton shroud
Positive
“Frost is coming,” he noted, touching the cotton shroud and wrinkled tunic.
Neg. (attr.)
“Frost is coming,” he noted, touching the wrinkled shroud and cotton tunic.
Neg. (obj.)
“Frost is coming,” he noted, touching the cotton tunic and wrinkled shroud .
triple_bind_cycle
Query
plain chair, decorative lamp and metallic table
Appendix
Table 9: Examples of the seven finetuning construction types. Each block shows a query, positive caption, and two hard negatives formed by permuting attributes or objects. Bold marks words moved relative to the positive.
Dataset
CLIP B/32
LABCLIP B/32
TripletCLIP B/32
READ-CLIP B/32
PE CORE-G
LamRA- Ret
Qwen3-VL Emb-2B
Qwen3-VL Emb-8B
Ours-2B
Ours-8B
Test set
62.9
62.2
57.6
65.0
65.4
56.2
57.1
60.4
84.0
93.6
deferred_bind_anaphoric
50.4
50.1
50.9
51.8
51.1
51.2
52.7
53.8
59.4
72.9
deferred_bind_respective
51.0
50.9
52.1
51.5
51.1
51.1
51.4
50.8
53.2
56.6
Appendix
Table 10: Triplet accuracy on held-out finetuning examples. Accuracy (%) on the in-distribution test set and the two held-out deferred-binding construction types. Both of our finetuned models outperform all baselines across all three evaluations. Best results are shown in bold.
SABER-MCQ
MMEB-v3
Model
T → T
T → I
I → T
I → I
Image
Video
VisDoc
Text
Agent
All
Qwen3-VL-Emb-8B-NoOverlap
99.3
65.7
71.8
93.1
72.6
58.8
75.5
43.1
42.6
55.3
Qwen3-VL-Emb-8B-Random
99.4
68.7
73.8
94.3
72.5
58.8
75.4
43.2
42.3
55.3
Qwen3-VL-Emb-8B-OverlapOnly
99.4
69.8
74.1
94.7
72.5
58.8
75.4
43.3
42.0
55.2
Qwen3-VL-Emb-8B-MixedLengths
99.6
70.6
77.1
94.8
72.3
58.8
75.6
42.9
42.6
55.2
Qwen3-VL-Emb-8B
53.7
34.9
36.3
84.9
73.7
59.6
74.3
43.7
39.1
54.7
Appendix
Table 11: Training-data ablation. SABER-MCQ and MMEB-v3 performance for lexical-overlap and query–candidate length ablations of our 8B model. SABER-MCQ reports 4-way accuracy, while MMEB-v3 reports Hit@1 for Image, Video, and Agent and NDCG@5 for VisDoc and Text. Best results are shown in bold.
SABER-MCQ
MMEB-v3
Model
T → T
T → I
I → T
I → I
Image
Video
VisDoc
Text
Agent
All
Qwen3-VL-Emb-8B-NoLiNeS
100.0
87.3
87.8
99.0
60.8
51.2
68.8
34.6
39.0
47.8
Qwen3-VL-Emb-8B
53.7
34.9
36.3
84.9
73.7
59.6
74.3
43.7
39.1
54.7
Ours-8B
99.3
69.0
74.1
94.3
72.5
58.7
75.4
43.1
42.3
55.2
Appendix
Table 12: LiNeS ablation. SABER-MCQ and MMEB-v3 performance for our 8B model before and after applying LiNeS. SABER-MCQ reports 4-way accuracy, while MMEB-v3 reports Hit@1 for Image, Video, and Agent and NDCG@5 for VisDoc and Text. Best results are shown in bold.
Figure 4: Layer-wise binding margin. Mean binding margin across the 36-layer text stack for test queries, their corresponding positive captions, and SABER queries. Finetuning preserves stronger binding in later layers, with a larger effect without LiNeS.
SABER-MCQ
MMEB-v3
Model
T → T
T → I
I → T
I → I
Image
Video
VisDoc
Text
Agent
All
Qwen3-VL-Emb-8B-Attn-LiNeS
99.4
70.0
74.8
94.2
72.4
58.6
75.2
42.8
42.2
55.0
Qwen3-VL-Emb-8B-Attn-NoLiNeS
100.0
86.4
87.2
99.2
59.5
50.5
66.3
34.8
39.2
47.2
Qwen3-VL-Emb-8B
53.7
34.9
36.3
84.9
73.7
59.6
74.3
43.7
39.1
54.7
Ours-8B
99.3
69.0
74.1
94.3
72.5
58.7
75.4
43.1
42.3
55.2
Appendix
Table 13: Attention loss ablation. SABER-MCQ and MMEB-v3 performance for our 8B model trained with the attention loss, with and without LiNeS. SABER-MCQ reports 4-way accuracy, while MMEB-v3 reports Hit@1 for Image, Video, and Agent and NDCG@5 for VisDoc and Text. Best results are shown in bold.
SABER-MCQ
MMEB-v3
Model
T → T
T → I
I → T
I → I
Image
Video
VisDoc
Text
Agent
All
UEmbed-2B
33.2
27.3
24.7
83.4
63.7
50.8
71.5
35.4
35.9
48.2
UEmbed-2B-Finetuned
81.8
39.2
39.8
88.3
62.2
48.9
67.8
31.9
34.2
45.6
UEmbed-9B
46.9
36.4
32.2
88.7
68.6
55.6
75.2
40.9
38.1
52.3
UEmbed-9B-Finetuned
91.2
57.3
49.7
94.6
67.6
55.1
74.5
40.4
35.9
51.3
WeMM-Embedding-2B
51.4
29.8
28.9
59.6
78.0
65.2
78.4
44.2
44.8
58.4
Appendix
Table 14: Generalization to additional embedding backbones. Performance of UEmbed and WeMM-Embedding on SABER and MMEB-v3 before and after binding-focused finetuning. Finetuning improves all four SABER modality pairings across both model families and scales, while largely preserving MMEB-v3 performance. SABER-MCQ reports 4-way accuracy, while MMEB-v3 reports Hit@1 for Image, Video, and Agent and NDCG@5 for VisDoc and Text. Best results per pretrained–finetuned pair are shown in bold.
SABER-MCQ 360 Test Examples (20%)
MMEB-v3
Finetuning Modalities
SABER Finetuning Data
T → T
T → I
I → T
I → I
Image
Video
VisDoc
Text
Agent
All
T → T
180 (10%)
87.2
40.6
46.7
87.5
73.8
59.8
74.8
43.7
39.3
54.9
360 (20%)
95.6
52.5
55.6
90.0
73.9
59.9
74.9
43.7
39.5
55.0
630 (35%)
96.9
54.7
59.4
90.6
73.8
59.9
75.0
43.8
39.7
55.1
1,260 (70%)
97.8
55.6
60.3
90.8
73.8
59.8
75.1
43.7
39.6
55.0
I → I
180 (10%)
56.1
32.8
39.4
95.3
73.9
59.6
74.6
43.7
39.2
54.8
Appendix
Table 15: Text vs. image finetuning on SABER. Performance of Qwen3-VL-Embedding-8B after finetuning with increasing amounts of SABER data using either text–text or image–image supervision. Text supervision yields stronger overall SABER performance and consistently better cross-modal transfer, while image supervision performs best on the matched image–image setting. SABER–MCQ reports 4-way accuracy on the fixed 360 -example test split, with all models evaluated at epoch 40 . MMEB-v3 reports Hit@1 for Image, Video, and Agent tasks and NDCG@5 for VisDoc and Text tasks. Best results are shown in bold.
Model
Art
Fashion
Household
Landmark
Product
Technology
Toy
All
# Classes
2
7
7
4
5
5
8
38
# Instances
33
92
50
136
36
49
95
491
Qwen3-VL-Emb-8B
75.4
62.4
72.4
76.1
66.0
76.6
52.5
66.6
Ours-8B
82.4
72.4
80.2
82.2
72.5
84.4
63.7
75.2
Appendix
Table 16: ILIAS fine-grained instance retrieval. Image–image retrieval mAP (%) averaged over the fine-grained classes within each top-level category; All averages over all 38 classes. Best results are shown in bold.
Figure 5: Qualitative image–image retrieval on ILIAS. Top-5 retrievals for two queries favoring Qwen3-VL-Embedding-8B (top) and two favoring Ours-8B (bottom). Green positives denote images of the same instance as the query, while red negatives denote other instances.
Figure 6: Qualitative fine-grained instance retrieval on ILIAS. Examples from three fine-grained classes under the category-restricted evaluation. For each query, we show the top-5 retrievals from Qwen3-VL-Embedding-8B and Ours-8B. Green positives depict the same instance as the query, while red negatives depict different instances from the same fine-grained class.
Figure 7: Agreement across attribute-binding formulations. Each point represents a model, comparing SABER accuracy on two-object image–text scenes with CLEVR-Bind accuracy. Performance is positively correlated across the ten models (Spearman ρ=0.89 ; Kendall τ=0.78 ), with Ours-8B achieving the highest accuracy in both settings.
Figure 8: Instruction trade-offs. Mean SABER-MCQ accuracy versus mean MMEB-v3 score on image tasks across 41 instruction choices for Qwen3-VL-Embedding-8B and our finetuned model (Ours-8B). Lines trace each model’s Pareto frontier over instructions, and circles indicate the default instruction.
Figure 9: Examples from attribute-binding benchmarks. Existing benchmarks span natural images, photo composites, diffusion-generated scenes, and synthetic 3D environments, with varying vocabulary sizes and numbers of bindings per sample.
Number of objects
Modalities
Model
2
3
4
5
6
7
8
9
10
Mean
T → T
CLIP ViT-B/32
55.5
57.5
61.5
60.0
55.5
56.0
54.0
41.5
40.5
53.6
LABCLIP ViT-B/32
58.0
57.5
64.0
62.5
55.0
57.0
55.0
46.5
41.5
55.2
TripletCLIP ViT-B/32
12.0
36.5
43.5
48.0
50.5
49.0
54.0
43.0
49.5
42.9
READ-CLIP ViT-B/32
41.0
49.5
52.5
55.5
50.0
50.5
51.0
39.5
36.5
47.3
PE-Core-bigG-14-448
60.0
64.5
74.0
79.5
70.0
71.0
65.0
57.0
54.0
66.1
Appendix
Table 17: SABER-MCQ accuracy across scene complexity. Accuracy (%) for 4-way MCQs across scenes with 2–10 objects, reported for all four modality pairings. Mean averages over object counts. Best and second-best results within each modality pairing and column are shown in bold and underlined, respectively.
Number of objects
Modalities
Model
2
3
4
5
6
7
8
9
10
Mean
T → T
CLIP ViT-B/32
75.7
77.4
80.4
76.2
74.1
74.7
73.7
70.2
63.3
74.0
LABCLIP ViT-B/32
77.0
76.1
81.3
77.0
73.0
72.8
73.3
74.2
63.7
74.3
TripletCLIP ViT-B/32
47.7
59.2
65.5
67.3
71.8
67.9
76.5
67.8
69.7
65.9
READ-CLIP ViT-B/32
66.0
67.1
71.6
75.9
68.8
71.1
73.4
64.3
57.7
68.4
PE-Core-bigG-14-448
78.2
79.2
85.8
89.7
82.3
82.2
84.5
76.0
72.4
81.1
Appendix
Table 18: SABER large-gallery retrieval on independent scenes. mAP (%) across scenes with 2–10 objects for the 100 independently generated queries at each scene size, reported for all four modality pairings. Mean averages over object counts. Best and second-best results within each modality pairing and column are shown in bold and underlined, respectively.
Number of objects
Modalities
Model
2
3
4
5
6
7
8
9
10
Mean
T → T
CLIP ViT-B/32
25.0
28.6
30.7
33.1
38.8
39.6
42.2
46.6
57.4
38.0
LABCLIP ViT-B/32
27.2
30.0
32.1
34.1
37.6
39.0
42.4
43.7
57.0
38.1
TripletCLIP ViT-B/32
18.8
25.5
28.3
31.1
33.3
36.2
41.8
45.3
62.1
35.8
READ-CLIP ViT-B/32
26.4
30.0
31.2
33.1
36.9
38.7
41.0
44.1
57.8
37.7
PE-Core-bigG-14-448
30.1
32.9
34.5
36.3
38.6
43.0
44.6
50.2
63.7
41.5
Appendix
Table 19: SABER large-gallery retrieval on nested chains. mAP (%) across scenes with 2–10 objects for the 100 nested-chain queries at each scene size, reported for all four modality pairings. Mean averages over object counts. Best and second-best results within each modality pairing and column are shown in bold and underlined, respectively.
Dataset
License
Model
License
NCD
MIT
CLIP ViT-B/32
MIT
VG-Attribution
MIT
LABCLIP ViT-B/32
MIT
ColorSwap
MIT
TripletCLIP ViT-B/32
Open
SugarCrepe-Swap-Att.
MIT
READ-CLIP ViT-B/32
MIT
SugarCrepe++-Swap-Att.
MIT
PE-Core bigG-14-448
Apache 2.0
BiVLC-Swap-Att.
MIT
LamRA-Ret
MIT
Appendix
Table 20: Licenses and usage terms of datasets and models used in this work.
Qilu University of Technology (Shandong Academy of Sciences), Jinan, China · China Telecom Digital Intelligence Technology Co., Ltd., Jinan, China · Shenyang Aerospace University, Shenyang, China +1