Written by Acorn Sales Company, manufacturing stamps and seals since 1964 · Reviewed by Holly R, VP of Sales and Marketing at Acorn Sales, against the Illinois Department of Financial and Professional Regulation, advised by the Board of Licensing for Professional Geologists and 225 ILCS 745/60 on 21 September 2026 · Updated 21 September 2026
An Illinois geologist seal is exactly one and three quarter inches in diameter, and it is the only Illinois design seal with a prescribed size. 68 Illinois Administrative Code 1252.APPENDIX A(a) requires each licensee to obtain, at their own expense, “a seal or rubber stamp, 1¾ inches in diameter” consisting of concentric circles, with LICENSED PROFESSIONAL GEOLOGIST in capitals in the upper portion between them, ILLINOIS in capitals in the lower portion, and your name and individual license number within the inner circle. Architects, professional engineers, structural engineers, land surveyors, landscape architects and registered interior designers all have no stated size in Illinois, so a supplier who has learned that Illinois never gives a dimension will get this one wrong.
Read the lower band twice. It says ILLINOIS alone. Every other Illinois design seal ends with State of Illinois, so a template will default to the wrong wording. A geologist device reading Licensed Professional Geologist, State of Illinois does not match the rule.
The sealing duty is the widest in this group, and it runs the opposite way from Texas and Pennsylvania. Section 60(b) of the Professional Geologist Licensing Act reaches “All preliminary, draft, and final geologic reports, documents, permits, affidavits, maps, boring logs, cross sections, or other records offered to the public,” and requires each to carry the full name, signature, license number, date of license expiration and an impression of the seal. Preliminary and draft material offered to the public is inside the duty, not outside it.
Illinois geologist seal requirements at a glance
| Requirement | Illinois rule | Source |
|---|---|---|
| Seal required | Yes | 225 ILCS 745/60 |
| Required elements | LICENSED PROFESSIONAL GEOLOGIST in capitals in the upper portion, between the concentric circles; ILLINOIS in capitals in the lower portion, between the concentric circles; Your name, within the inner circle; Your individual license number, within the inner circle | 68 Ill. Adm. Code 1252.APPENDIX A(a) |
| Size and shape | One and three quarter inches in diameter. | 68 Ill. Adm. Code 1252.APPENDIX A(a) |
| Device allowed | A seal or a rubber stamp, at the licensee’s own expense. | 68 Ill. Adm. Code 1252.APPENDIX A(a) |
| Signature and date | Full name, signature, license number, date of license expiration and seal impression, all on the record. | 225 ILCS 745/60(b) |
| What must be sealed | Very wide, and expressly including work that most states exempt. | 225 ILCS 745/60(b), (c), (d), (e) |
| Electronic seal | Not addressed. Neither section 60 of the Act nor 68 Illinois Administrative Code 1252.APPENDIX A mentions an electronic or digital seal or signature, and Part 1252 carries no electronic sealing provision. Checked the. | 225 ILCS 745/60 |
| Renewal and lapse | Every license issued under the Professional Geologist Licensing Act expires on March 31 of odd numbered years, renewable during the month preceding the expiration date. | 68 Ill. Adm. Code 1252.70(a) |
| Firm requirements | Not addressed. Section 60 puts no firm identifier on the document and Part 1252 carries no design firm registration rule of the kind that governs Illinois architects at 68 Ill. Adm. Code 1150.80 and Illinois land. | 225 ILCS 745/60 |
| Regulator | The Illinois Department of Financial and Professional Regulation, advised by the Board of Licensing for Professional Geologists | Professional Geologist Licensing Act, 225 ILCS 745, principally § 60 (Seals) |
Is a seal required in Illinois?
Section 60(a) of the Professional Geologist Licensing Act provides that “Upon licensure, each licensee shall obtain a seal of a design as required by rule bearing the licensee’s name, license number, and the legend ‘Licensed Professional Geologist’.” Section 60(b) then sets a sealing duty wider than almost any other state in this group: “All preliminary, draft, and final geologic reports, documents, permits, affidavits, maps, boring logs, cross sections, or other records offered to the public and prepared or issued by or under the supervision of a Licensed Professional Geologist shall include the full name, signature, and license number of the licensee, and the date of license expiration of the person who prepared the document or under whose supervision it was prepared, and an impression of the licensee’s seal, in accordance with rules issued by the Department.” The design rule is 68 Illinois Administrative Code 1252.APPENDIX A.
What must appear on the seal
- LICENSED PROFESSIONAL GEOLOGIST in capitals in the upper portion, between the concentric circles
- ILLINOIS in capitals in the lower portion, between the concentric circles
- Your name, within the inner circle
- Your individual license number, within the inner circle
Appendix A(a) is precise about geometry and case: the device “shall consist of concentric circles between which shall appear in capital letters ‘ILLINOIS’ in the lower portion of the seal and ‘LICENSED PROFESSIONAL GEOLOGIST’ in the upper portion of the seal. Within the inner circle of the seal shall appear the name of the licensee and the individual’s license number.” Note that the bottom band reads ILLINOIS alone, not State of Illinois, which is the wording every other Illinois design seal uses. Subsection (b) calls the printed figure a suggested facsimile, so the artwork is guidance while the lettering and the concentric circle construction are mandatory. The license expiration date is required on the document, not inside the seal.
Size and shape
One and three quarter inches in diameter. Appendix A(a) requires each licensee to obtain, at the licensee’s own expense, “a seal or rubber stamp, 1¾ inches in diameter.” This is a single fixed figure and not a range, and it is the only prescribed dimension among the Illinois design professions. Architects, professional engineers, structural engineers, land surveyors, landscape architects and registered interior designers all have no stated size in Illinois.
Embosser, rubber stamp or digital
A seal or a rubber stamp, at the licensee’s own expense. Appendix A(a) names both, and section 60(b) of the Act asks for “an impression of the licensee’s seal” on the record. The safe buy is an inked rubber or self inking stamp at exactly one and three quarter inches, because Illinois geology output is reports, boring logs and cross sections that travel as copies and a dry embossed impression does not reproduce.
Signing and dating
Full name, signature, license number, date of license expiration and seal impression, all on the record. Section 60(b) names the five together. The date required is the date of license expiration of the person who prepared the document or under whose supervision it was prepared, which is a license attribute rather than a signing date, and it is the element most often missed. No provision requires the signature to cross the seal.
Illinois geologists seal their drafts, and theirs is the only Illinois seal with a size
Section 60(b) of the Act is the widest sealing duty in this set. It reaches “All preliminary, draft, and final geologic reports, documents, permits, affidavits, maps, boring logs, cross sections, or other records offered to the public.” Most states take the opposite approach and either exempt preliminary work or require it to be labeled instead of sealed. Texas geoscience gives preliminary documents a prescribed release sentence in place of a seal. Illinois seals them.
Which documents must be sealed
Very wide, and expressly including work that most states exempt. Section 60(b) reaches “All preliminary, draft, and final geologic reports, documents, permits, affidavits, maps, boring logs, cross sections, or other records offered to the public.” Preliminary and draft material is inside the duty rather than outside it, provided it is offered to the public. Section 60(c) allocates responsibility on multi party work: the Licensed Professional Geologist who has contract responsibility seals a cover sheet of the professional work products and those individual portions for which that geologist is legally and professionally responsible, and a Licensed Professional Geologist practicing as the support professional seals those individual portions for which that geologist is responsible. Section 60(d) makes use of the seal a representation that the work was prepared and administered in accordance with the standards of reasonable professional skill and diligence, and section 60(e) makes it unlawful to affix a seal in a way that masks the true identity of the person who exercised direction, supervision and responsible charge, while protecting a sealing geologist from damage caused by later unauthorized changes or uses.
Electronic and digital seals
Not addressed. Neither section 60 of the Act nor 68 Illinois Administrative Code 1252.APPENDIX A mentions an electronic or digital seal or signature, and Part 1252 carries no electronic sealing provision. Checked the whole of Part 1252, whose sections run from 1252.10 to 1252.120 plus Appendix A. That is a notable gap given that the Illinois architect statute and the Illinois landscape architect rule both state expressly that the seal and dates may be electronically affixed.
Renewal, lapse and retirement
Every license issued under the Professional Geologist Licensing Act expires on March 31 of odd numbered years, renewable during the month preceding the expiration date. Because section 60(b) requires the date of license expiration on the document rather than in the seal, the device itself survives renewal and the license number does not change. A device that engraved the expiration date would be obsolete on a fixed statewide schedule, which is a good reason not to. Nothing in section 60 or Part 1252 requires the seal to be surrendered or destroyed.
Firm requirements
Not addressed. Section 60 puts no firm identifier on the document and Part 1252 carries no design firm registration rule of the kind that governs Illinois architects at 68 Ill. Adm. Code 1150.80 and Illinois land surveyors at 1270.45. Checked section 60 and the whole of Part 1252. The seal content is closed by Appendix A(a) to the legend, the name and the individual license number, so no firm data belongs on the die in any case.
What to check before you order
Order a seal or rubber stamp exactly one and three quarter inches in diameter, built as two concentric circles. Between the circles, LICENSED PROFESSIONAL GEOLOGIST in capitals across the upper portion and ILLINOIS in capitals across the lower portion. Inside the inner circle, your name and your individual license number. Note that the lower band reads ILLINOIS alone; do not let a template default to State of Illinois. Choose ink rather than a dry embosser, since Illinois geology work travels as copies. Leave space on the document for the full name, signature, license number and date of license expiration that section 60(b) requires alongside the impression, and remember that preliminary and draft records offered to the public are sealed in Illinois, not merely labeled.
Browse geologist stamps and seals.
Frequently asked questions
Is a geologist seal required in Illinois?
Yes. Section 60(a) of the Act provides that “Upon licensure, each licensee shall obtain a seal of a design as required by rule bearing the licensee’s name, license number, and the legend ‘Licensed Professional Geologist’,” and section 60(b) requires an impression of it on the records it names. The design rule is 68 Illinois Administrative Code 1252.APPENDIX A.
What size is an Illinois geologist seal?
One and three quarter inches in diameter, a single fixed figure rather than a range, under Appendix A(a). It is the only prescribed dimension among the Illinois design professions, so do not let a supplier size it by analogy with an Illinois architect or engineer stamp.
Does the bottom band read State of Illinois?
No. Appendix A(a) requires ILLINOIS in capitals in the lower portion, between the concentric circles, and LICENSED PROFESSIONAL GEOLOGIST in capitals in the upper portion. The architect, engineer, structural engineer, land surveyor, landscape architect and interior designer legends all end with State of Illinois, and the geologist one does not.
What goes inside the inner circle?
Your name and your individual license number, and nothing else. Appendix A(b) calls the printed figure a suggested facsimile, so the artwork is guidance while the lettering and the concentric circle construction are mandatory. The license expiration date is required on the document rather than inside the seal.
Do I really have to seal drafts?
If they are offered to the public, yes. Section 60(b) reaches all preliminary, draft and final geologic reports, documents, permits, affidavits, maps, boring logs, cross sections or other records offered to the public and prepared or issued by or under the supervision of a licensee. Most states take the opposite approach: Texas geoscience gives preliminary documents a prescribed release sentence in place of a seal, and Illinois seals them.
What has to appear beside the seal?
Four things, under section 60(b): your full name, your signature, your license number, and the date of license expiration of the person who prepared the document or under whose supervision it was prepared. That date is a license attribute rather than a signing date, and it is the element most often missed. A one line stamp cannot carry the block, so leave room on the document.
Rubber stamp or embosser in Illinois?
Appendix A(a) names a seal or rubber stamp, and section 60(b) asks for an impression of the licensee’s seal on the record. An inked rubber or self-inking stamp at exactly one and three quarter inches is the practical buy, because Illinois geology output is reports, boring logs and cross sections that travel as copies, and a dry embossed impression does not reproduce.
Can I seal an Illinois geologic report electronically?
Neither section 60 nor 68 Illinois Administrative Code 1252.APPENDIX A mentions an electronic or digital seal or signature, and Part 1252 carries no electronic sealing provision anywhere in its sections from 1252.10 to 1252.120. That is a notable gap, since the Illinois architect statute and the Illinois landscape architect rule both say expressly that the seal and dates may be electronically affixed. Ask the Department before treating a PDF impression as satisfying section 60(b).
Who seals what when several geologists work on a project?
Section 60(c) splits it. The Licensed Professional Geologist with contract responsibility seals a cover sheet of the professional work products and those individual portions for which that geologist is legally and professionally responsible, and a Licensed Professional Geologist practicing as the support professional seals those individual portions for which that geologist is responsible. Section 60(e) makes it unlawful to affix a seal in a way that masks the true identity of the person who exercised direction, supervision and responsible charge.
Does my Illinois seal go stale at renewal?
No. Licenses expire on 31 March of odd numbered years and are renewable during the preceding month, and because section 60(b) requires the expiration date on the document rather than in the seal, the device survives renewal and the license number does not change. A die with an engraved expiration date would be obsolete on a fixed statewide schedule, which is a good reason not to order one. Nothing requires the seal to be surrendered or destroyed.
