40mm vs 42mm vs 45mm vs 50mm Round Self-Inking Stamps
A factory-direct comparison of the four main round self-inking stamp sizes: which imprint diameter fits your logo, your text and your buyers.
Quick Answer
The right round self-inking stamp size depends on how much information your imprint must carry. Choose 40mm for a standard company seal with a logo and circular text, 42mm when the company name is long or the logo needs more breathing room, 45mm for complex logos or several lines of text, and 50mm for the largest round impressions and bold branding marks. All four Hongli R-Series sizes share the same ABS housing, self-inking mechanism and replaceable ink pad, and all support custom logos, shell colors and private label packaging.
Size Comparison Table
All four sizes are produced in-house at the Hongli factory in Dongguan, China, with the same OEM options. MOQ is 100 pcs per design and samples are available in 3 days.
| Size | Best For | Impression Area | Logo / Text Capacity | OEM |
|---|---|---|---|---|
| 40mm Round Self-Inking Stamp | Compact business stamps and standard company seals | 40mm round | Medium | Available |
| 42mm Round Self-Inking Stamp | Company seals with longer business names | 42mm round | Medium–Large | Available |
| 45mm Round Self-Inking Stamp | Larger logos and multi-line text | 45mm round | Large | Available |
| 50mm Round Self-Inking Stamp | Large logos and bold branding impressions | 50mm round | Extra Large | Available |
40mm Overview
The 40mm round self-inking stamp (R-40) is the best-selling size in the Hongli R-Series. A 40mm imprint fits a company logo in the center with the company name in circular text around it, which makes it the standard choice for company seals, office approval stamps and loyalty stamps.
For detailed specifications, MOQ and OEM options, see the 40mm Round Self-Inking Stamp product page.
42mm Overview
The 42mm round self-inking stamp (R-42) keeps the same compact housing style as the 40mm model but adds two millimeters of imprint diameter. That extra space helps when the company name is long or when the logo contains fine detail that would look crowded at 40mm.
For specifications and wholesale terms, see the 42mm Round Self-Inking Stamp product page.
45mm Overview
The 45mm round self-inking stamp (R-45) is the step-up size for complex artwork: multi-line text, detailed emblems and official-style seals with several rings of wording all stay readable at 45mm.
For specifications and wholesale terms, see the 45mm Round Self-Inking Stamp product page.
50mm Overview
The 50mm round self-inking stamp (R-50) is the largest standard round model in the R-Series. It is built for large logos, bold brand marks and designs that combine a detailed graphic with several lines of text.
For specifications and wholesale terms, see the 50mm Round Self-Inking Stamp product page.
Which Size Should You Choose?
A practical way to decide:
- Logo only, short name — 40mm is usually enough and keeps the stamp compact.
- Logo plus a long company name — move up to 42mm so the circular text stays readable.
- Detailed emblem or several text lines — choose 45mm for cleaner reproduction.
- Maximum visual impact — choose 50mm for bold branding and large round designs.
If you are not sure, send your artwork to the Hongli team. We prepare a free digital proof within 3 days so you can see exactly how your design looks at each size before you commit to a size.
Logo and Text Space
Imprint diameter controls two things: how large the central logo can be, and how much circular text fits around it without the characters becoming too small to read. As a rule of thumb from our production experience, moving one size up lets you either enlarge the logo or add one more line of text — not both at the same time.
For very small wording, registration numbers or dense layouts, our team may recommend adjusting the artwork instead of simply choosing a bigger stamp.
OEM Considerations
All four sizes are available through the same OEM Self-Inking Stamps program: custom logo plates, custom housing colors, private label packaging and mixed-size orders under one MOQ structure of 100 pcs per design. Samples are produced in 3 days and bulk production takes 15-25 days depending on quantity.
Distributors often combine sizes in one shipment — for example 40mm and 45mm — so their customers can serve both standard office buyers and branding-focused buyers. See Round Self-Inking Stamps for the full category.
Written by: Hongli Content Team · Technical review: Hongli Production Team · Last updated: October 30, 2026
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Round Stamp Size Guide FAQ
Common buyer questions about choosing between 40mm, 42mm, 45mm and 50mm round self-inking stamps.
What size round stamp is best for a company logo?
For most company seals with a logo and circular company name, the 40mm round self-inking stamp is the standard choice. If the name is long or the logo is detailed, the 42mm or 45mm sizes give the artwork more room.
What is the difference between 40mm and 42mm stamps?
The 42mm stamp has an imprint 2mm wider in diameter than the 40mm model, in a similar compact housing. That extra space keeps longer company names and finer logo details readable.
Can I order a custom round self-inking stamp with my own logo?
Yes. Every Hongli round stamp is produced from your artwork with a free digital proof in 3 days. Custom logo plates, housing colors and private label packaging are all available under OEM.
Can different sizes be mixed in one order?
Yes. Different sizes, models and ink colors can be mixed in one wholesale order, with MOQ counted per design at 100 pcs.
Is the ink pad replaceable on all four sizes?
Yes. All R-Series round stamps use a slide-out replaceable ink pad, available in black, blue, red, green and violet.